Solution Guide for Migrating Oracle on UNIX to SQL Server - Willy .Net

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong>on UNIX to SQL Server on WindowsPublished April 2005

ivContentsBuild the Physical Design ................................................................................................................48Incorporate Design Considerations.........................................................................................................50Hardware Design Considerations ....................................................................................................50Validate the Technology .........................................................................................................................50SQL Server Editions and Features ..................................................................................................51Windows Server 2003......................................................................................................................52Technical Proof of Concept .............................................................................................................52Develop the Project Plans.......................................................................................................................53Development Plan ...........................................................................................................................53Stabilizing Phase Plans ...................................................................................................................55Test Plan .........................................................................................................................................55Pilot Plan .........................................................................................................................................59Deployment Plan .............................................................................................................................60Create the Project Schedules .................................................................................................................63Estimating the Ef<strong>for</strong>t ........................................................................................................................63Set Up the Development and Test Environments ...................................................................................65Developing: Databases — Introduction .................................................................................... 67Introduction and Goals............................................................................................................................67<strong>Migrating</strong> the Database...........................................................................................................................68Developing: Databases — <strong>Migrating</strong> the Database Architecture ........................................... 71Introduction and Goals............................................................................................................................71Build the SQL Server Instance................................................................................................................71Pre-Installation Planning..................................................................................................................72Installation .......................................................................................................................................72Configure the Server...............................................................................................................................73Configure Memory ...........................................................................................................................74Set the CPU Affinity.........................................................................................................................76Configure the Listener .....................................................................................................................77Migrate the Storage Architecture ............................................................................................................77Blocks ..............................................................................................................................................77Extents and Segments.....................................................................................................................78Tablespaces and Datafiles ..............................................................................................................79Storage Definition <strong>for</strong> Tables and Indexes.......................................................................................81Migrate System Storage Structures.................................................................................................82Developing: Databases — <strong>Migrating</strong> Schemas ........................................................................ 83Introduction and Goals............................................................................................................................83Scripting Migrated Schema Objects........................................................................................................84Script Everything..............................................................................................................................84Provide Support Documentation......................................................................................................84Protect the Scripts ...........................................................................................................................84Migrate the Schema................................................................................................................................85Map the Storage Architecture ..........................................................................................................85Create Databases <strong>for</strong> the Schema...................................................................................................87Create Filegroups <strong>for</strong> the Tablespaces............................................................................................90Add Datafiles to Filegroups..............................................................................................................90Add Transaction Logs......................................................................................................................91Sample Schema Migration...............................................................................................................91Migrate the Schema Objects...................................................................................................................98Create the Schema Owner ..............................................................................................................98Create the Schema Objects...........................................................................................................102Comments .....................................................................................................................................111Constraints ....................................................................................................................................111Triggers .........................................................................................................................................119Indexes ..........................................................................................................................................121Views .............................................................................................................................................123Stored Programs............................................................................................................................126<strong>Solution</strong>s <strong>for</strong> Objects not Found in SQL Server .............................................................................129Sample Schema Object Migration .................................................................................................132

ContentsvDeveloping: Databases — <strong>Migrating</strong> the Database Users .................................................... 143Introduction and Goals..........................................................................................................................143Create User Accounts...........................................................................................................................143Create Roles and Grant Privileges .......................................................................................................145Sample User Migration .........................................................................................................................147Developing: Databases — <strong>Migrating</strong> the Data........................................................................ 153Introduction and Goals..........................................................................................................................153Planning the Data Migration..................................................................................................................153Options <strong>for</strong> Migration .....................................................................................................................153Factors in Migration .......................................................................................................................155Migration Strategy..........................................................................................................................156Executing the Data Migration................................................................................................................157Pre-Implementation Tasks.............................................................................................................158Implementation Tasks....................................................................................................................160Post-Implementation Tasks ...........................................................................................................165Validating the Data Migration.........................................................................................................165Developing: Databases — Unit Testing the Migration........................................................... 167Introduction and Goals..........................................................................................................................167Objectives of Testing ............................................................................................................................167The Testing Process.............................................................................................................................168Test Database Integrity..................................................................................................................169Test Security..................................................................................................................................169Validate Data .................................................................................................................................170Validate the Migration ....................................................................................................................170Developing: Applications — Introduction............................................................................... 173Introduction and Goals..........................................................................................................................173Application Migration Strategies ...........................................................................................................174Interoperation ................................................................................................................................174Port or Rewrite to .NET Framework...............................................................................................175Port or Rewrite to Win32................................................................................................................175Quick Port Using Windows Services <strong>for</strong> UNIX...............................................................................176Scenarios and Cases............................................................................................................................176Developing: Applications —<strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL............................................ 177Introduction ...........................................................................................................................................177<strong>Migrating</strong> Data Access..........................................................................................................................177Sample Tables...............................................................................................................................179Migration Process Overview ..........................................................................................................181Step 1: Extraction of Data Access .................................................................................................182Step 2: Transaction Management..................................................................................................202Step 3: Fetch Strategy ...................................................................................................................203Step 4: Subprograms Conversion..................................................................................................206Step 5: Job Scheduling..................................................................................................................213Step 6: Interface File Conversion...................................................................................................217Step 7: Workflow Automation ........................................................................................................217Step 8: Per<strong>for</strong>mance Tuning..........................................................................................................218Developing: Applications — <strong>Migrating</strong> Perl............................................................................ 223Introduction and Goals..........................................................................................................................223Introduction to the Perl DBI Architecture...............................................................................................224Scenario 1: Interoperation of Perl on UNIX with SQL Server................................................................225Case 1: Interoperating an ODBC DBD Application........................................................................226Case 2: Interoperating an <strong>Oracle</strong> DBD Application........................................................................228Scenario 2: Porting the Perl Application to Windows ............................................................................232Case 1: Porting a Perl Application using ODBC DBD....................................................................232Case 2: Porting a Perl Application Using <strong>Oracle</strong> DBD...................................................................234Developing: Applications — <strong>Migrating</strong> PHP ........................................................................... 237Introduction and Goals..........................................................................................................................237PHP Modules........................................................................................................................................238Scenario 1: Interoperating PHP on UNIX with SQL Server...................................................................240Case 1: Interoperating a PHP Application Using ORA Functions ..................................................240

viContentsCase 2: Interoperating a PHP Application Using OCI8 Functions.........................................................244Case 3: Interoperating a PHP Application Using ODBC Functions.......................................................246Common Function Translation Issues ..................................................................................................249Handling Transactions ...................................................................................................................249<strong>Migrating</strong> Cursors ..........................................................................................................................250Connection Pooling........................................................................................................................251Stored Procedures.........................................................................................................................251Scenario 2: Porting the Application to Win32........................................................................................252Case 1: Porting a PHP Application using ORA Functions .............................................................252Case 2: Porting a PHP Application Using OCI8 Functions ............................................................252Case 3: Porting a PHP Application Using ODBC Functions ..........................................................253Developing: Applications — <strong>Migrating</strong> Java .......................................................................... 255Introduction and Goals..........................................................................................................................255Scenario 1: Interoperating Java on UNIX with SQL Server...................................................................256Case 1: Interoperating a Java Application Using the JDBC Driver ................................................256Scenario 2 — Porting the Application to Win32 ....................................................................................259Developing: Applications — <strong>Migrating</strong> Python ...................................................................... 261Introduction and Goals..........................................................................................................................261Scenario 1: Interoperating Python on UNIX with SQL Server ...............................................................263Case 1: Interoperating Using the mxODBC Module ......................................................................263Scenario 2: Port the Python Application to Win32 ................................................................................266Case 1: Porting a Python Application using mxODBC...................................................................266Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Pro*C ............................................................ 269Introduction and Goals..........................................................................................................................269Understanding the Technology .............................................................................................................270Understanding Pro*C.....................................................................................................................270Understanding .NET and ADO.NET ..............................................................................................270Scenario 1: Rewriting Pro*C to the .NET Plat<strong>for</strong>m................................................................................271Case 1: Rewrite the Application using Visual Basic.NET...............................................................271Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Forms ........................................................... 279Introduction and Goals..........................................................................................................................279Migration Approach...............................................................................................................................279Examining <strong>Oracle</strong> Forms ......................................................................................................................281Object Library ................................................................................................................................284PL/SQL Library ..............................................................................................................................284Form Module .................................................................................................................................285Menu Module.................................................................................................................................288Windows and Canvases ................................................................................................................288Understanding Visual Basic .NET.........................................................................................................290Scenario 1: Rewriting to Visual Basic .NET ..........................................................................................291Case 1: Using <strong>Oracle</strong> Designer .....................................................................................................291Case 2: Manually Redesigning the Application..............................................................................291Testing the Visual Basic .NET Application ............................................................................................295Stabilizing Phase ....................................................................................................................... 297Introduction and Goals..........................................................................................................................297Testing the <strong>Solution</strong> ..............................................................................................................................298Best Practices................................................................................................................................299Preparing <strong>for</strong> Testing .....................................................................................................................299Types of Testing ............................................................................................................................301Bug Tracking and Reporting ..........................................................................................................305User Acceptance Testing and Signoff............................................................................................308Piloting the <strong>Solution</strong> ..............................................................................................................................308Preparing <strong>for</strong> the Pilot ....................................................................................................................309Conducting the Pilot.......................................................................................................................309Evaluating the Pilot ........................................................................................................................310Finalizing the Release...........................................................................................................................310Deploying Phase........................................................................................................................ 313

ContentsviiIntroduction and Goals..........................................................................................................................313Deploying the <strong>Solution</strong>..........................................................................................................................313Deploying the Database Server.....................................................................................................314Deploying the Server Side Applications.........................................................................................317Deploying the Client Application ....................................................................................................318Change Management ....................................................................................................................320Stabilizing the Deployment ...................................................................................................................320Deployment Checklist ....................................................................................................................320Quiet Period...................................................................................................................................323Transferring Ownership to Operations..................................................................................................324Project Team Tasks.......................................................................................................................324Operations Team Tasks ................................................................................................................325Conducting Project Review and Closure...............................................................................................325Operations.................................................................................................................................. 327Introduction and Goals..........................................................................................................................327Operational Framework ........................................................................................................................327Windows Environment Operations........................................................................................................328System Administration ...................................................................................................................328Security Administration ..................................................................................................................328Monitoring......................................................................................................................................329Additional Links .............................................................................................................................329SQL Server Environment Operations ...................................................................................................329Administration................................................................................................................................329Security..........................................................................................................................................330Monitoring......................................................................................................................................330Additional Links .............................................................................................................................330APPENDICES ............................................................................................................................. 331Appendix A: SQL Server <strong>for</strong> <strong>Oracle</strong> Professionals................................................................................331Architecture ...................................................................................................................................331Administration................................................................................................................................343Appendix B: Getting the Best Out of SQL Server 2000 and Windows ..................................................348Per<strong>for</strong>mance ..................................................................................................................................348Scalability ......................................................................................................................................349High Availability .............................................................................................................................349Features and Tools........................................................................................................................351Appendix C: Baselining.........................................................................................................................353Creating Baselines.........................................................................................................................353Capturing Statistics........................................................................................................................357Comparing and Reporting Results.................................................................................................357Appendix D: Installing Common Drivers and Applications ....................................................................358Installing FreeTDS ................................................................................................................................358Configuring FreeTDS.....................................................................................................................358Testing the FreeTDS Configuration ...............................................................................................358Installing unixODBC..............................................................................................................................359Installing ActiveState Perl .....................................................................................................................360Appendix E: Reference Resources.......................................................................................................362

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on WindowsixPrefaceOverviewThe <strong>Oracle</strong> on UNIX to SQL Server on Windows Migration <strong>Guide</strong> provides practicalguidance on the processes and procedures to be followed while migrating from <strong>Oracle</strong>databases (versions 8i and later) on UNIX plat<strong>for</strong>ms toMicrosoft® Windows® Server 2003 and Microsoft SQL Server 2000. This guide alsopresents strategies and procedural guidance to convert existing applications <strong>for</strong> usewithin the SQL Server 2000 and Microsoft Windows Server environment. This guideprovides additional in<strong>for</strong>mation and references to online resources about migrating othercomponents of your application ecosystem, including the server and networkinfrastructure, development and test environment, and user accounts.The guide is based on the experience of consultants working in the field andorganizations that have successfully migrated from an <strong>Oracle</strong> on UNIX to a SQL Serveron Windows environment, and it comprises the best lab-tested, customer-proven, crossproducttechnical guidance from Microsoft on planning, building, deploying, and operatingthe migration solution. All processes and procedures contained in this guide have beenvalidated through the Microsoft Technology Adoption Program (TAP), which is a betaprogram that consists of customers and partners who have evaluated and validated thevarious technologies and practices described in this guide.An important assumption made in this guide is that your organization has decided tomigrate all or parts of the <strong>Oracle</strong> database and application environment from UNIX toSQL Server 2000 in a Windows environment. Because of this assumption, this guidedoes not present a competitive analysis of <strong>Oracle</strong> versus SQL Server 2000, or UNIXversus Windows. This guide does help you decide which migration strategy is best <strong>for</strong>your organization given your specific business and technical requirements, and itexplains how to plan <strong>for</strong> and execute that strategy.This process-driven approach to migration is applied to the <strong>Oracle</strong> database, the UNIXapplications that rely on the database, and the application programming interfaces (APIs)that connect the applications to the database. The strategies and methods <strong>for</strong> migratingthese components vary according to the size and complexity of the database, application,and infrastructure of the <strong>Oracle</strong> source system. The strategies and methods also varyaccording to any new business or technical requirements your organization develops as aresult of migrating to the Microsoft Windows plat<strong>for</strong>m.Because there is so much variance in the possible approaches to migration, this guideprovides numerous examples and best practices to help you better understand both theconcepts and detailed processes involved in migration. A series of job aids (templates,spreadsheets, and questionnaires) are included as part of this solution guide to help youbetter analyze, plan, structure, and per<strong>for</strong>m the migration.The in<strong>for</strong>mation under the following two headings outlines the technical scope of themigration strategies and methods provided in this guide.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windowsxi● Migration of the operating system to Microsoft Windows Server 2003●●Support <strong>for</strong> Open Management Group (OMG), an open-source, java-basedstandard <strong>for</strong> metadataData extraction from enterprise resource planning (ERP) systemsWhile these technical subjects are not explicitly discussed in this guide, in<strong>for</strong>mation aboutmany of them is available from Microsoft. Where appropriate throughout this guide, linksto more in<strong>for</strong>mation are provided.Intended AudiencesGenerally, the intended audience <strong>for</strong> this solution guide includes medium and large-sizedIT organizations that want to migrate their database and applications from <strong>Oracle</strong> onUNIX to SQL Server 2000 on Windows. More specifically, this guide is written <strong>for</strong> all ofthe members of the migration team, from business decision makers to development tooperations. As a result, not all chapters in this guide are relevant to all team members,and the knowledge prerequisites <strong>for</strong> using this guide are expressed as an aggregate ofthe knowledge required of the team. The rest of this section provides brief descriptions ofthe typical audiences <strong>for</strong> this guide, followed by a brief statement of the aggregateknowledge prerequisites <strong>for</strong> developing the solution described in this guide. The intendedaudience <strong>for</strong> individual chapters is identified in the "How to Use This <strong>Solution</strong> <strong>Guide</strong>"section later in this Preface.The following list organizes common job titles and organizational responsibilities underthe Microsoft <strong>Solution</strong>s Framework (MSF) role most commonly associated with that titleor responsibility. The relationship between this solution guide and MSF is discussed inmore detail in the "How to Use This <strong>Solution</strong> <strong>Guide</strong>" section. In some organizations, arole may be filled by a single team member or many.● Stakeholders and High Level Decision Makers. These team members can besubdivided into two groups:● Business Decision Makers (BDMs). This group often includes the CIO and ITdirector of an organization. These personnel decide the business priorities <strong>for</strong>purchasing and implementing solutions within the organizations. IT BDMsrequire a high-level understanding of the technical solutions being explored sothat they can assess the value that the solution can provide to theorganization.● Technical Decision Makers (TDMs). The focus of TDMs is to determine thetechnology used to solve business problems. IT TDMs must understand thebusiness drivers the organizations face along with the functionality delivered bymultiple technology scenarios.●●Product Management Role. This role usually includes team members with thefollowing job title and responsibilities:● Product Manager. This team member acts as a link between the teammembers of the project and the customers of the solution by handling highlevelcommunication and managing the customer's expectations. The ProductManager ensures that the team addresses the customer's needs, concerns,questions, and feedback throughout the project. Product managers mustunderstand the business needs of the solution, including operations, businessprocesses, and policies.User Experience Role. This role usually includes team members with thefollowing job titles and responsibilities:

xiiPreface●Usability Expert or Technical Writer/Editor. Ensures that the new solution iseasy <strong>for</strong> customers to use. The Usability Experts ensure that documentationand training is provided to end users to use the new solution effectively.●●●●Program Management Role. This role usually includes team members with thefollowing job title and responsibilities:●Project Managers. These personnel are responsible <strong>for</strong> managing theresources and schedule <strong>for</strong> the migration project from start to end.Development Role. This role usually includes team members with the followingjob titles and responsibilities:●●●●●●●●IT Architect. The primary role of the IT architect is to carry out decisions madeby the TDMs. Team members with this responsibility are most involved duringthe Planning, Developing, and Stabilizing Phases of the migration project.<strong>Oracle</strong> Database Administrators. These personnel are knowledgeable aboutthe physical characteristics, logical characteristics, per<strong>for</strong>mance, and servicerequirements of the source database. These personnel also have knowledgeof any scripts and tools that are used in database administration.SQL Server Database Administrators. These personnel are expert inarchitecting and implementing SQL Server databases. These team memberswill design the target SQL Server database environment and per<strong>for</strong>m key tasksduring the actual migration.UNIX System Administrators. These personnel have complete knowledge ofthe UNIX servers and the operating system installations, such as versions,packages, configuration, and security.Windows System Administrators. These personnel have completeknowledge of the Windows operating system and the Microsoft applicationproduct line. These team members should have some experience in definingand implementing server technologies in Windows.UNIX Application Developers. These personnel have knowledge of theapplications that are running in the current UNIX environment and theirimplementation details.Windows Application Developers. These personnel have per<strong>for</strong>meddevelopment in the Windows environment <strong>for</strong> the technologies involved in thesolution.Security Specialists. These personnel have a wide base of knowledge aboutsecurity issues, including how security relates to networks, servers, databases,and applications.Test Role. This role usually includes team members with the following job titlesand responsibilities:● Test Engineering Managers. These personnel have knowledge about testingapplication and database solutions and also have managerial experience.● UNIX Database and Applications Testers. These personnel have knowledgeabout all databases and applications that are running in the current UNIXenvironment and provide input when test plans are created <strong>for</strong> the migratedenvironment.● Windows Database and Applications Testers. These team members haveknowledge of databases and applications in both UNIX and Windows. Thesepersonnel are experienced at creating and executing test plans.Release Management Role. This role usually includes team members with thefollowing job titles and responsibilities:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windowsxiii●●Deployment Manager. These personnel have knowledge of managing thedeployment of the new database and applications in the productionenvironment.Technology Specialist. These personnel have knowledge of the technologyand processes in a data center operation. They have intimate knowledge of thesolution being developed and will aid in transitioning them into the productionenvironment.Knowledge PrerequisitesIt is assumed that the technically-oriented audience <strong>for</strong> this guide has, in aggregate, thefollowing specific technology competencies and proficiencies:● Expert level of UNIX development and administration● Expert level of Windows development and administration● Expert level of SQL Server and <strong>Oracle</strong> administration● Knowledgeable staff to maintain the new environment and the technologiesinvolved● Knowledgeable staff that understand any interaction between the UNIX andWindows environment when interoperability is created and maintainedHow to Use This <strong>Solution</strong> <strong>Guide</strong>The organization of this guide is based on the industry-proven need to manage ITprojects according to a disciplined process that improves the likelihood of the project'ssuccess. It is designed to be used with a companion guide, the UNIX Migration Project<strong>Guide</strong> (UMPG). While this guide contains the technical and solution-specific in<strong>for</strong>mationneeded <strong>for</strong> the project, the UMPG provides the disciplined process steps <strong>for</strong> using thisin<strong>for</strong>mation in the context of a migration project and a team organization model ("peopleand process" guidance).To facilitate their side-by-side use, both guides use project phases as an organizationaldevice. Specifically, they follow the structure of the Microsoft <strong>Solution</strong>s Framework(MSF), which defines five distinct phases <strong>for</strong> IT projects: Envisioning, Planning,Developing (or <strong>Migrating</strong>), Stabilizing, and Deploying. Each guide presents thein<strong>for</strong>mation (process or technical) needed <strong>for</strong> a phase within chapters named <strong>for</strong> thatphase. For example, in the solution guide, business and technical in<strong>for</strong>mation needed <strong>for</strong>the initial decision-making is in the Envisioning chapter and detailed procedures andscripts are in the <strong>Migrating</strong> chapters.The UMPG is essentially "MSF applied to UNIX migration projects." It begins with anoverview of MSF and then describes the processes that belong to each phase and theteam roles responsible <strong>for</strong> them — it is not, however, meant to serve as a comprehensiveintroduction to MSF. In-depth in<strong>for</strong>mation about MSF is available to interested readers onthe Microsoft <strong>Solution</strong>s Frameworks Web site at http://www.microsoft.com/msf.The reason <strong>for</strong> separating the process guidance from technical and project-specificguidance is to keep this guide as lean as possible. It is recognized that some readersneed to focus narrowly on project tasks, while persons with project management andteam lead responsibilities need to digest the UMPG guidance and apply it to the project.Because organizational personnel and project team members tend to have differentlevels of involvement during different phases, the division of content according to projectphase also supports the ability to focus on the material that is most relevant to aparticular responsibility.

xivPrefaceIt is important <strong>for</strong> you to note the content scope of this guidance. The applicationmigration and interoperation-related in<strong>for</strong>mation in this solution only discusses issuespertaining to the database connectivity logic. It does not discuss general applicationporting issues between UNIX and Windows such as mapping UNIX system calls toWindows APIs and migrating the graphical user interface (GUI). For detailed in<strong>for</strong>mationabout UNIX to Windows application migration, refer to the UNIX Application Migration<strong>Guide</strong> (UAMG) available at http://msdn.microsoft.com/library/default.asp?url=/library/enus/dnucmg/html/ucmglp.asp.Note Although the two guides are designed to be used together, it is not necessary tofollow the MSF processes and team guidance described in the UMPG if theorganization has an alternative project methodology in place. In that case, the UMPGwould be used merely to map the MSF phases and team structure to the elements ofthe organization's methodology. Readers who will use this guide to implement a projectshould read at least the overview of MSF in the UMPG to familiarize themselves withthe MSF Process Model, the MSF Team Model, and MSF terminology.Figure 0.1 represents the chapters of interest to readers with different areas ofresponsibility.Figure 0.1Chapters of interest by team role

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on WindowsxvOrganization by ChapterThe following chapter list provides an overview of the content and structure of this guide.●●●●●●●●●●●●●●●Preface.Chapter 1: Introduction to the Microsoft <strong>Solution</strong>s Framework. This chapterprovides a brief introduction to the Microsoft <strong>Solution</strong>s Framework (MSF) and howit is applied to migration projects.Chapter 2: Envisioning Phase. This chapter provides guidance to carry out thevarious activities of the Envisioning Phase in an <strong>Oracle</strong> on UNIX to SQL Server onWindows migration project. These activities include understanding your businessand technical goals, assessing your current situation at a high level, building ahigh-level solution concept, setting up the project team, and assessing projectrisks.Chapter 3: Planning Phase. This chapter provides guidance to carry out thevarious activities of the Planning Phase in an <strong>Oracle</strong> on UNIX to SQL Server onWindows migration project. These activities include creating a detailed assessmentof the current environment, developing the solution design and architecture, andproducing detailed project plans and project schedule.Chapter 4: Developing: Databases — Introduction. This chapter introduces thedifferent tasks in migrating the <strong>Oracle</strong> database to SQL Server 2000.Chapter 5: Developing: Databases — <strong>Migrating</strong> the Database Architecture.This chapter describes the steps <strong>for</strong> creating an instance of SQL Server which isequivalent in architecture to the original <strong>Oracle</strong> database.Chapter 6: Developing: Databases — <strong>Migrating</strong> Schemas. This chapter showshow to migrate a schema owner and its objects to a SQL Server database.Chapter 7: Developing: Databases — <strong>Migrating</strong> the Database Users. Thischapter contains detailed steps <strong>for</strong> creating users in the SQL Server databasesand granting them the same kind of privileges they had in the original <strong>Oracle</strong>database.Chapter 8: Developing: Databases — <strong>Migrating</strong> the Data. This chapter exploresthe different options <strong>for</strong> migrating the application data from <strong>Oracle</strong> to SQL Server.It provides details in the usage of each of the options.Chapter 9: Developing: Databases — Unit Testing the Migration. This chaptercontains the processes <strong>for</strong> testing the migrated database, its objects, and data.Chapter 10: Developing: Applications — Introduction. This chapter introducesthe procedures to migrate the application and the API (the connectivity tierbetween the database and the application) from the existing solution to theproposed solution.Chapter 11: Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL.This chapter provides specific steps and procedures <strong>for</strong> converting SQLstatements and PL/SQL code <strong>for</strong> use with SQL Server.Chapter 12: Developing: Applications — <strong>Migrating</strong> Perl. This chapter providesspecific steps and procedures <strong>for</strong> migrating Perl applications to the SQL Server onWindows environment.Chapter 13: Developing: Applications — <strong>Migrating</strong> PHP. This chapter providesspecific steps and procedures <strong>for</strong> migrating PHP applications to the SQL Server onWindows environment.Chapter 14: Developing: Applications — <strong>Migrating</strong> Java. This chapter providesspecific steps and procedures <strong>for</strong> migrating Java applications to the SQL Server onWindows environment.

xviPreface●●●●●●●●●●Chapter 15: Developing: Applications — <strong>Migrating</strong> Python. This chapterprovides specific steps and procedures <strong>for</strong> migrating Python applications to theSQL Server on Windows environment.Chapter 16: Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Pro*C. This chapterprovides specific steps and procedures <strong>for</strong> migrating Pro*C applications to the SQLServer on Windows environment.Chapter 17: Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Forms. This chapterdiscusses the options available <strong>for</strong> migrating an <strong>Oracle</strong> Forms-based application.Chapter 18: Stabilizing Phase. In this chapter, the solution is tested in anenvironment similar to the production environment. This chapter describes thevarious testing options and processes that can be implemented to ensure thequality of the solution.Chapter 19: Deploying Phase. This chapter describes the procedure <strong>for</strong> movingthe solution into the production environment and transferring ownership of thesolution to operations. The chapter also identifies the tests that need to beper<strong>for</strong>med on the solution during deployment.Chapter 20: Operations. This chapter provides references to existing operationalguides to administer a Windows-based server infrastructure and SQL Server 200based databases.Appendix A: SQL Server <strong>for</strong> <strong>Oracle</strong> Professionals. This appendix providesin<strong>for</strong>mation to help <strong>Oracle</strong> DBAs who do not have SQL Server experience learnabout its administration.Appendix B: Getting the Best Out of SQL Server 2000 and Windows. Thisappendix provides reference to material to optimize and take advantage of SQLServer and Windows.Appendix C: Baselining. This appendix provides detailed in<strong>for</strong>mation aboutcollecting statistics in SQL Server.Appendix D: Installing Common Applications and Drivers. This appendixprovides installation instructions <strong>for</strong> applications and drivers that may be usedwhile migrating the application.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on WindowsxviiDocument ConventionsThis guide uses the style conventions shown in Table 0.1.Table 0.1: Document ConventionsText ElementMeaningBold textBold text is used in the context ofparagraphs <strong>for</strong> commands; literalarguments to commands (including pathswhen they <strong>for</strong>m part of the command);switches; and programming elements,such as methods, functions, data types,and data structures. User interfaceelements are also identified with bold font.Italic textItalic text is used in the context ofparagraphs <strong>for</strong> variables to be replaced bythe user. It is also used to emphasizeimportant in<strong>for</strong>mation.Monospace fontUsed <strong>for</strong> excerpts from configuration files,code examples, and terminal sessions.Monospace bold fontUsed to represent commands or other textthat the user types.Monospace italic fontUsed to represent variables the readersupplies in command line examples andterminal sessions.UPPERCASETransact-SQL keywords and SQLelements.%SystemRoot% The folder in which Windows Server 2003is installed.Job AidsThe job aids included with this guide can be used to support the various tasks per<strong>for</strong>medduring the different phases of the migration. The aids are in the <strong>for</strong>m of questionnaires,tools, and templates used <strong>for</strong> designing, planning, and managing the migration project.The job aids are either in Microsoft Excel spreadsheet or Microsoft Word document<strong>for</strong>mat. They are available in the Tools and Templates folder in the zip file download ofthis guidance at http://go.microsoft.com/fwlink/?LinkId=45289.The purpose of providing job aids is to help you speed up the development of yourproject documents. New or additional guidance is not provided in the job aids. Instead,the job aids are generic templates that you should customize to fit your requirements.

xviiiPrefaceTable 1.2: Job Aids DescriptionsJob AidVision/ScopeProject StructureMigration Risk Exposure Rating FormAssessing the Current EnvironmentTemplateDevelopment PlanTest PlanPilot PlanDeployment PlanDescriptionUse this template to describe the goals ofthe project and the approaches that theteam will use to achieve those goals.Use this template to define how the projectis structured and managed and how thesolution will be created. This template willhelp you control and coordinate the entireproject.This spreadsheet will help you identify thepossible migration risks and theirconsequences. In addition, this documentalso helps you to prioritize the risks andprepare a mitigation plan <strong>for</strong> each risk.This template provides separatespreadsheets to assist in assessing theapplication, database, and serverenvironments.This template helps you to describe thesolution development process used <strong>for</strong> theproject. This plan provides the technicaldetails of what will be built, and it providesconsistent guidelines and processes to theteams creating the solution.This template helps you to describe thestrategy and approach used to plan,organize, and manage the project’s testingactivities. It identifies testing objectives,methodologies and tools, expected results,responsibilities, and resourcerequirements.This template contains in<strong>for</strong>mation to helpprepare and execute a successful pilot. Itincludes pilot scope, user interactions andpilot evaluationThis template helps you to describe theactions necessary <strong>for</strong> a smoothdeployment and transition to ongoingoperations. It covers the processes ofpreparing, installing, testing, training, andtransferring the solution to operations.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on WindowsxixContributorsThe following organizations and individuals contributed to this project.Program ManagerDhilip Gopalakrishnan (Microsoft)AuthorScalability ExpertsEditorsThomas Olsen (Volt Technical Services)Gaile Simmons (Microsoft)ArchitectsPeter Skjøtt Larsen (Microsoft)Jason Zions (Microsoft)TestSandor Kiss (Microsoft)Infosys TechnologiesFeedbackPlease direct questions and comments about this guide to cisfdbk@microsoft.com.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 11Introduction to the Microsoft<strong>Solution</strong>s FrameworkIntroduction and GoalsFor large-scale projects, such as database migrations, it is vital to have a cohesive andstructured project framework in place. This foundation ensures that projects are carefullyplanned, roles and tasks are clearly identified and defined, and that the thousands ofcrucial details are addressed <strong>for</strong> a successful migration.In this chapter, you will learn about Microsoft <strong>Solution</strong>s Framework (MSF), which hasbeen used successfully on numerous IT projects. This adaptable and robust projectframework provides a comprehensive structure that assists in guiding the project from theinitial planning stages until after the project has been completed. If you are familiar withMSF, skip this chapter and continue with Chapter 2, "Envisioning Phase."Overview of MSFEvery successful project follows a methodology to achieve its objectives. Themethodology employed in this migration guide is the Microsoft <strong>Solution</strong>s Framework. Avast amount of in<strong>for</strong>mation about MSF is available from Microsoft, and the UNIXMigration Project <strong>Guide</strong> provides a thorough explanation of MSF <strong>for</strong> specific audiences ofthis migration guide, such as the team members that fulfill the Program Managementrole. Yet not every team member on your migration project needs in-depth knowledge ofMSF to successfully per<strong>for</strong>m their team function. Because this is the case, the followingbrief overview is intended to provide all team members with a high-level overview of MSFthat will familiarize them with basic concepts and terminology and help them to betterunderstand the specific sections of this migration guide that they will need to read,understand, and execute.MSF was created to maximize the success of IT projects throughout the entire IT lifecycle. This in<strong>for</strong>mation is derived from the experience gained within Microsoft on largescalesoftware development and service operation projects, the experience of Microsoft’sconsultants, and common best practices from the worldwide IT industry.As opposed to a prescriptive methodology, MSF provides a flexible and scalableframework to meet the needs of any sized organization or project team. MSF guidanceconsists of principles, models, and disciplines <strong>for</strong> managing the people, process, and

2Introduction to the Microsoft <strong>Solution</strong>s Frameworktechnology elements that most projects encounter. A detailed introduction to the MSFmodels and disciplines is available at http://www.microsoft.com/msf.MSF Foundational PrinciplesAt the core of MSF are eight foundational principles. For detailed in<strong>for</strong>mation on the eightfoundational principles, download the MSF Version 3 Overview fromhttp://msdn.microsoft.com/vstudio/enterprise/msf/.The eight foundational principles of MSF are:● Foster open communications. The MSF Process Model enables an open andfree flow of in<strong>for</strong>mation among the team members and key stakeholders to preventmisunderstandings and reduce the probability that work will have to be redone.Documenting the progress of the project and making it available to the teammembers, stakeholders, and customers can best achieve this.● Work toward a shared vision. The MSF Process Model provides a phase (theEnvisioning Phase) and a separate milestone (Vision/Scope Approved) <strong>for</strong> creatinga shared vision. A vision includes detailed understanding of the goals andobjectives that the solution needs to achieve. A shared vision highlights theassumptions that the team members and customers have <strong>for</strong> the solution.● Empower team members. Empowering the team members implies that themembers accept responsibility and ownership of work assigned to them. Teamempowerment can be achieved by preparing schedules where the team memberscommit to complete their work on a fixed date. This makes the team members feelaccountable and also provides a method <strong>for</strong> identifying any potential delays earlyin the project.● Establish clear accountability and shared responsibility. The MSF TeamModel is based on the principle that each role is accountable <strong>for</strong> the quality of thesolution. All the team members share the overall responsibility of the projectbecause the project can fail due to a mistake made by a single member.● Focus on delivering business value. The solution must deliver value to theorganization in the <strong>for</strong>m of business value. This business value is achieved onlyafter the solution is completely deployed into the production environment.● Stay agile, expect change. MSF assumes that the solution will encountercontinuous changes be<strong>for</strong>e being deployed to the production environment. Theteam should be aware and prepared to manage such changes.● Invest in quality. In MSF, each team member is responsible <strong>for</strong> the quality of thesolution. To confirm the quality throughout the project's duration, a test team is<strong>for</strong>med. This ensures that the solution meets the quality level of the stakeholders.● Learn from all experiences. MSF states that the experiences derived from oneproject should be used and shared with teams in other projects. Theseexperiences can also help to identify the best practices that should be followed inyour organization.The MSF Team Model — OverviewThe MSF Team Model was developed over a period of several years to compensate <strong>for</strong>some of the disadvantages imposed by the top-down, hierarchical structure of traditionalproject teams. Teams organized under the MSF Team Model are small andmultidisciplinary teams of peers, although the model is scalable <strong>for</strong> both small and largeprojects. Team members share responsibilities and balance each other’s competenciesto keenly focus on the project at hand. They are expected to share a common project

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 3vision, a focus on deploying the project, high standards <strong>for</strong> quality and communication,and a willingness to learn. Figure 1.1 shows the role clusters of the MSF Team Model.Figure 1.1The MSF Team ModelThe MSF Team Model emphasizes the importance of aligning role clusters (commonlyreferred to simply as "roles") to business needs. It does this by organizing each rolearound a quality goal that the project must meet to be successful. Each role aggregates a"cluster" of related functional areas and responsibilities. The functional areas eachrequire a different discipline and focus, but are related in that they contribute towardmeeting the quality goal.The result is a well-balanced team whose skills and perspective represent all of thefundamental project goals. For team members, possessing a clearly defined role andowning a clearly defined goal is motivational. It increases the understanding ofresponsibilities, and ultimately leads to a better solution. Because each goal is critical tothe success of a project, the roles that represent these goals are considered to be equallyimportant. Persons filling the roles are given equal say in critical decisions and arethought of as peers. MSF teams are known as "teams of peers." Table 1.1 associateseach role cluster with a quality goal.Table 1.1: Role Clusters and Quality GoalsRole ClusterProgram ManagementDevelopmentTestUser ExperienceRelease ManagementProduct ManagementGoalDeliver the solution within project constraintsBuild to specificationApprove <strong>for</strong> release only after all product qualityissues are identified and addressedEnhance user effectivenessAchieve smooth deployment and ongoing operationsSatisfy customersThe MSF Process Model — OverviewThe MSF Process Model describes a high-level sequence of activities <strong>for</strong> building anddeploying IT solutions. Rather than prescribing a specific series of procedures, it isflexible enough to accommodate a broad range of IT projects. MSF combines twoindustry standard models: the waterfall model, which emphasizes the achievement ofmilestones, and the spiral model, which focuses on the continual need to refine the

4Introduction to the Microsoft <strong>Solution</strong>s Frameworkrequirements and estimates <strong>for</strong> a project. An innovative aspect of the MSF processmodel is that it covers the life cycle of a solution from project inception to live deployment.This helps project teams focus on customer business value, because no value is realizeduntil the solution is deployed and in operation.Figure 1.2The MSF Process Model showing phases and major milestonesMSF is a milestone-driven process. Milestones fall at the end of each phase and containcriteria <strong>for</strong> completing the phase. Important deliverables must have been completed andcritical questions, such as: Does the team agree on the project scope? Have we plannedenough to proceed? Have we built what we said we would build? Is the solution workingproperly <strong>for</strong> the customer? must be satisfactorily answered. The project team and keystakeholders review the deliverables and reach agreement that the project can proceedto the next phase in a milestone meeting.MSF is also an iterative process. The process model is designed to accommodatechanging project requirements by iterating through short development cycles andincremental versions of the solution.The iterative aspect of the MSF process applies well to migration projects, which arefrequently driven by an iterative process. In some cases, the migration task itself isapproached iteratively. The first cycle migrates limited, basic functionality to the newplat<strong>for</strong>m; and subsequent cycles add additional capabilities to the new environment untilit is equivalent to the original, unmigrated technology. In some other migration projects,the first cycle completely migrates some technology to a new environment, whilesubsequent cycles extend the technology beyond its original capabilities. Iterativeapproaches to migration projects provide a means to control project risk and creategreater flexibility to accommodate changing requirements.The MSF Process Model originated with the process used by Microsoft to developapplications. This model may be applied to traditional application developmentenvironments, but is equally appropriate <strong>for</strong> the development and deployment ofenterprise infrastructure solutions, Web development, e-commerce, and distributedapplications.Although the Program Management Role orchestrates the overall process within eachphase, the successful achievement of each milestone requires special leadership andaccountability from each of the other team roles. As a project moves sequentially througheach phase, the level of ef<strong>for</strong>t <strong>for</strong> each of the roles varies. The use of milestones helps tomanage this ebb and flow of involvement in the project.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 5Table 1.2: Major Milestones and Primary DriversMilestoneVision/Scope ApprovedProject Plans ApprovedScope CompleteRelease Readiness ApprovedDeployment CompletePrimary Driver(s)Product ManagementProgram ManagementDevelopment and User ExperienceTest and Release ManagementRelease ManagementEach phase also has interim milestones that lead to the achievement of the final phasemilestone. Recommended interim milestones are shown in Figure 1.3, but they may needto be modified <strong>for</strong> a particular project.Figure 1.3MSF Process Model with interim milestonesThe MSF Disciplines — OverviewMSF makes use of three classic disciplines, Risk Management, Readiness Management,and Project Management, which it has adapted to fit the framework. They are reflected inboth the Process Model and the role responsibilities defined in the Team Model. Thissection describes each discipline briefly. For a thorough discussion of each discipline andits application within MSF, see the respective white papers available athttp://msdn.microsoft.com/vstudio/enterprise/msf/.Risk ManagementThe MSF Risk Management Discipline advocates proactive risk management, continuousrisk assessment, and integration into decision-making throughout the project andoperational life cycle. Risks are continuously assessed, monitored, and actively manageduntil they are either resolved or the possible negative event happens and the risks have

6Introduction to the Microsoft <strong>Solution</strong>s Frameworkbecome real problems to be handled as such. The MSF risk management processdefines six logical steps the team uses to manage current risks, plan and execute riskmanagement strategies, and capture knowledge <strong>for</strong> the enterprise. Figure 1.4 illustratesthe relationship between the six steps.Figure 1.4The MSF risk management processThe following list provides detailed in<strong>for</strong>mation about each of the six risk managementsteps.● Identify. The process of risk identification calls <strong>for</strong> all team members to participatein surfacing risks to make the team aware of potential problems. As the input to therisk management process, risk identification should be undertaken as early aspossible and repeated frequently throughout the project life cycle.● Analyze and Prioritize. Risk analysis trans<strong>for</strong>ms the estimates or data aboutspecific project risks that surface during risk identification into a <strong>for</strong>m that the teamcan use to make decisions regarding prioritization. Risk prioritization enables theteam to commit project resources to manage the most important risks.● Plan and Schedule. Risk planning takes the in<strong>for</strong>mation obtained from riskanalysis and prioritization and uses it to <strong>for</strong>mulate strategies, plans, and actions.Risk scheduling ensures that these plans are approved and then incorporated intothe project management process and infrastructure to ensure that riskmanagement is carried out as part of the day-to-day activities of the team. Riskscheduling explicitly connects risk planning with project planning.● Track and Report. Risk tracking monitors the status of specific risks and theprogress in their respective action plans. Risk tracking also includes monitoring theprobability, impact, exposure, and other measures of risk <strong>for</strong> changes that couldalter priority, risk plans, and project features, resources, or schedule. Risk trackingenables visibility of the risk management process within the project from theperspective of risk levels as opposed to the task completion perspective of thestandard operational project management process. Risk reporting ensures that theteam, sponsor, and other stakeholders are aware of the status of project risks andthe plans to manage them.● Control. Risk control is the process of executing risk action plans and theirassociated status reporting. Risk control also includes initiation of project changecontrol requests when changes in risk status or risk plans could result in changesin project features, resources, or schedule.● Learn. Risk learning <strong>for</strong>malizes the lessons learned from the project, collects therelevant project artifacts and tools, and captures that knowledge in reusable <strong>for</strong>m.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 7Readiness ManagementThe MSF Readiness Management Discipline defines readiness as a measurement of thecurrent state versus the desired state of knowledge, skills, and abilities (KSAs) ofindividuals in an organization. This measurement is the real or perceived capabilities ofthe individuals at any point during the ongoing process of planning, building, andmanaging solutions.Each role on a project team includes key functional areas that the individuals undertakingthose roles must be capable of fulfilling. Individual readiness is the measurement of thestate of an individual with regard to the KSAs needed to meet the responsibilities requiredof their particular role. The MSF Readiness Management Discipline includes a process tohelp teams prepare <strong>for</strong> the KSAs needed to build and manage projects and solutions.The most basic approach to the readiness process is simply to assess skills and makeappropriate changes through training. On projects that are small or have shorttimeframes, this streamlined approach is quite effective. For longer term or serialprojects, organizations can benefit from per<strong>for</strong>ming the steps of defining the skillsneeded, evaluating the results of change produced by training, and keeping track ofKSAs. This allows <strong>for</strong> the full realization of readiness management, and is typically whereorganizations reap the rewards of investments in readiness activities.The readiness management process is composed of four steps: Define, Assess, Change,and Evaluate. Each process step includes a series of tasks to help reach the next step.Figure 1.5The readiness management processDefineThis step focuses on defining requirements. It identifies and describes the scenarios,competencies, and proficiency levels needed to successfully plan, build, and manage thesolutions. It also determines which roles in the team should be proficient in the definedcompetencies. Depending on the role, the individual filling it may need to be proficient inone or many of the defined competencies.Scenarios describe the different types of activities that occur in a typical enterprise.Scenarios generally fall into one of four categories defined in terms of the business valuethey offer the organization — High Potential, Strategic, Key Operational, and Support.Different scenarios call <strong>for</strong> different types of skills and knowledge and distinct approachesto obtaining the appropriate resources and skills <strong>for</strong> that project type.

8Introduction to the Microsoft <strong>Solution</strong>s Framework●●●●High Potential. These focus on the situations an IT department encounters whenplanning and designing to deploy, upgrade, or implement a new product,technology, or service in its organization. These are typically research typesituations in which the technology is brand new or in beta <strong>for</strong>m. The organizationneeds to have a high degree of agility and the capability to investigate andevaluate new technologies. For these scenarios, it needs to be prepared to obtain(<strong>for</strong> a short period) the best expertise available.Strategic. Scenarios in this category focus on the situations an IT department islikely to encounter when exploiting new technologies, products, or services. Theseare typically market-leading solutions that could lead to business trans<strong>for</strong>mationdefining the to-be long-term architecture. Here the organization needs in-house, indepthexpertise at the solution architect level and the capability of bridging skillsacross technology to the business.Key Operational. Scenarios in this category focus on the situations an ITdepartment is likely to encounter once it has deployed, upgraded, or implementeda new product, technology, or service that has to coexist, or continue to seamlesslyinteract with legacy software and systems. These are typically today's businesscriticalsystems, aligned with the as-is technology architecture. Quality of technicalknowledge and process are critical, as is ready availability of the skills applicable tothe relevant technologies. The challenges are easier to plan <strong>for</strong> when thetechnologies are proven. Typically, organizations obtain the readiness and skillsneeded in this scenario by out-sourcing or by developing strong in-housecapability.Support. Scenarios in this category focus on situations in which it is necessary toextend the product to fit the needs of a customer’s environment. These aretypically valuable but not business-critical solutions and often involve legacytechnology. Here, cost of delivery becomes paramount and the organization maydecide to rely on external skills (particularly <strong>for</strong> legacy) on a reactive basis.When determining the most appropriate scenario <strong>for</strong> a migration project, keep in mindthat the technology being migrated was initially deployed under one scenario. Forexample, it might have been implemented when the technology was new, or it might havebeen a key operational technology. As the new migrated environment is envisioned,though, a different scenario may apply. If the technology has matured, <strong>for</strong> example, whatwas a “high potential” project may be treated, in migration, as a “key operational”scenario. Alternatively, what might have originally been a classical support-scenarioproject might involve, as a result of migration to newer technology, something more akinto the high potential scenario. Identifying the most appropriate scenario helps to map theappropriate competencies and proficiencies required <strong>for</strong> the migration.● Competencies describe the measurable objectives, or tasks, in a given scenariothat an individual needs to be able to complete with proficiency. A singlecompetency is used to define a major part of an individual’s job or job responsibilityrelating to per<strong>for</strong>mance. A competency can be considered a combination of skills,knowledge, and per<strong>for</strong>mance requirements● Proficiencies are the measure of the capability to execute tasks associated with aparticular competency within a given scenario. An individual's proficiency levelprovides a baseline <strong>for</strong> analyzing the gap between that individual's current skill setand the necessary skills <strong>for</strong> completion of the tasks associated with the givenscenario.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 9AssessThe assess step focuses on the individual team members. It determines thecompetencies that these individuals currently possess. It is during this step that analysisof the competencies as they relate to the various job roles is undertaken to determine theskills of individuals within each of these roles. The desired competencies are thenanalyzed against the current competencies — the “to-be" versus the “as-is.” This workenables the development of learning plans, so that desired competency levels can bereached. The following tasks need to be per<strong>for</strong>med to complete the assess step:● Measure individuals' knowledge, skills, and abilities through self-assessments orskills assessments (tests).● Analyze gaps by comparing the individual's KSA measurements to the expectedproficiency level <strong>for</strong> the role. Individuals can then concentrate on bridging thesegaps through the use of learning plans.● Create learning plans that identify the appropriate resources and methods (such astraining materials, courseware, white papers, computer based training, mentoring,on-the-job, and self-directed training) to fill the gaps. Learning plans should consistof both <strong>for</strong>mal and in<strong>for</strong>mal learning activities, and guide individuals through theprocess of moving from one proficiency level to the next.ChangeIn this step, individuals advance their skills through learning in order to bridge the gapbetween their current proficiency and desired proficiency levels. In this step, the followingtasks are accomplished:● Train individuals using the actual training, hands-on learning, and mentoringtechniques described in the learning plans.● Track the learning of each individual. Monitor and report the progress of individualsand their skills by scenario and competency. Tracking progress enables individualand overall readiness to be determined at any time in the life cycle.EvaluateThis step determines whether the learning plans were effective and whether the lessonslearned were successfully implemented on the job. At this point it is time to:● Review results to see if more training is necessary or if what was learned is beingimplemented on the job.● Manage knowledge to foster the sharing of the new intellectual resources. Thissharing of knowledge enhances the collective knowledge of the solution team andthe enterprise and fosters a learning community. Additionally, a <strong>for</strong>mal knowledgemanagement system can provide a way to share common and repeatable bestpractices that help reduce costs and risks <strong>for</strong> other project teams.The MSF Readiness Management Discipline is considered an ongoing, iterativeapproach to readiness. Following the steps in the process helps manage the varioustasks required to align individual, project team, or organizational KSAs. It can lead tobetter individual, project team, and strategic planning success.

10Introduction to the Microsoft <strong>Solution</strong>s FrameworkProject ManagementThe third important discipline adopted by MSF is the Project Management Discipline. Todeliver a solution within project constraints, strong project management skills areessential. The MSF Team Model does not contain a role known as Project Manager;however, most project management functions are conducted by the MSF ProgramManagement Role.Project management is a set of skills and techniques that include:● Integrating planning done <strong>for</strong> each aspect of the project.● Conducting change control.● Defining and managing the scope of the project.● Preparing a budget and managing costs.● Preparing and tracking schedules.● Getting the right resources allocated to the project.● Managing contracts and vendors, and procuring project resources.● Facilitating team and external communications.● Facilitating the risk management process.● Documenting and tracking the team’s quality management process.Three distinctive characteristics of the MSF approach to project management stand out:● Most of the responsibilities of the role commonly known as "Project Manager" areencompassed in the MSF Program Management Role Cluster. As the size andcomplexity of a project grows, this role cluster is broken out into two branches ofspecialization: one dealing with architecture and specifications and the otherdealing with project management.● In larger projects requiring scaled-up MSF teams, project management activitiesoccur at multiple levels. As the teams grow in number, the project managementactivities become distributed among the team leads <strong>for</strong> each of the MSF teamroles. The Program Management Role is then responsible <strong>for</strong> management of the“rolled up” work from the leads in order to manage the entire solution.● Some large or complex projects require a specialist Project Manager or projectmanagement team. As the size, complexity, or risk becomes very large, oftenspecialist roles or teams are created to focus on one particular area. For theProgram Management Role, this can be done to break the many projectmanagement tasks into smaller, more manageable responsibility areas. Thesecould include a specialist project manager, risk manager, solution architect,schedule administrator, and so on.The differentiating factor of the MSF approach to project management is that the projectmanagement job function and activities do not impose a hierarchical structure on thedecision-making process. MSF advocates against a rigid, “dictator” project managementstyle because it works against an effective team of peers.The team of peers approach is a key success factor of MSF. All roles in MSF areconsidered equally important and major decisions are arrived at by consensus of the coreteam. If that consensus cannot be achieved, the Program Management Role plays atiebreaker function, making the final decision on the issue by transitioning into a decisionleader to drive the project <strong>for</strong>ward. This decision is made from the perspective of meetingthe customer’s requirements and delivering the solution within the constraints. Afterward,the team immediately resumes their normal peer relationships.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 11Overview of MSF PhasesThe in<strong>for</strong>mation in this section describes the MSF phases that structure the organizationof this migration guide. These phases create the structure used <strong>for</strong> the project throughoutthe rest of this guide.Envisioning PhaseIn the Envisioning Phase, the team identifies the vision and scope of the project bypreparing a vision and scope document.During this phase, goals <strong>for</strong> the project are <strong>for</strong>med and a vision statement is created thatdefines the entire project. This shared vision helps the team to work towards a commonobjective. The project team is assembled and the team members are empowered byhaving roles and responsibilities assigned to them.Another important activity in this phase is the identification of risks and preparation ofmitigation and contingency plans. The risks identified and the mitigation plans are usedthroughout the life cycle of the project. Refer to Chapter 2, "Envisioning Phase," <strong>for</strong> moredetails on the tasks and deliverables of the Envisioning Phase.Planning PhaseDuring this phase, the existing environment is assessed to <strong>for</strong>m a solution design. Themain activity of this phase is to do a detailed planning to ensure success of the project. Inthis phase, a master project plan deliverable is created that consists of all sub-plans,such as the test plan, and development plan.The plan focuses on budgets, quality, schedule, and the technical implementation of thesolution. The project team follows these plans in the subsequent phases. Refer toChapter 3, "Planning Phase," <strong>for</strong> more details on the tasks and deliverables of thePlanning Phase.Developing PhaseDuring this phase, the application components undergo trans<strong>for</strong>mation based on thedevelopment plans.Components that need a rewrite are developed. In components that are ported, changesbased on syntax compliancy, per<strong>for</strong>mance, and security are carried out. The source codeand executables help to create the deliverables of this stage. Refer to Chapter 4,"Developing: Databases — Introduction," <strong>for</strong> more in<strong>for</strong>mation on how to migrate adatabase. Chapter 10, "Developing: Applications — Introduction," provides differentscenarios <strong>for</strong> migrating an application.Stabilizing PhaseDuring this phase, all the components are tested collectively to ensure that the entiresolution operates properly.The testing criteria include achieving the desired functionality, security, and per<strong>for</strong>mancerequirements. To ensure this, both white box and black box testing are per<strong>for</strong>med. Thetested database and components <strong>for</strong>m the deliverables of this stage.Once testing is complete, the solution must be stabilized to ensure that it meets definedquality levels. If the migration is complex, a pilot test of the application can also beper<strong>for</strong>med during the Stabilizing Phase. Refer to Chapter 18, "Stabilizing Phase," <strong>for</strong>more details on the tasks and deliverables of the Stabilizing Phase.

12Introduction to the Microsoft <strong>Solution</strong>s FrameworkDeploying PhaseIn this phase, the team deploys the solution and ensures that it is stable and can beused. The tested solution is moved into production and transferred to operations.During this phase, the solution components are tuned in the production environment. Asolution signoff is obtained from all stakeholders that confirms that the application meetsthe requirements developed during the Envisioning and Planning Phases. Refer toChapter 19, "Deploying Phase," <strong>for</strong> more details on the tasks and deliverables of theDeploying Phase. The migration project and the guidance are deeply rooted in the MSFmethodology, and the chapters are in chronological order of the MSF phases startingfrom Chapter 2, "Envisioning Phase, through Chapter 19, "Deploying Phase."

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 132Envisioning PhaseIntroduction and GoalsThis chapter provides the process and technical in<strong>for</strong>mation required to complete theEnvisioning Phase of an <strong>Oracle</strong> on UNIX to SQL Server on Windows® migration project.The Envisioning Phase is an early stage of planning. This is the period during which theteam, the customer, and the sponsors define the high-level requirements and overallgoals of the project. The main purpose of the work per<strong>for</strong>med during the phase is toensure a common vision and reach consensus among the team members that the projectis both valuable to the organization and likely to succeed. During the Envisioning Phase,the focus is on creating clear definitions of the problem and understanding the high levelapproach to solving the problem. This sets a solid foundation from which specific planscan be developed during the Planning Phase and executed during all subsequent phasesto achieve the migration objectives. The Envisioning Phase culminates in theVision/Scope Approved Milestone.The key deliverables <strong>for</strong> the project team during the Envisioning Phase are:● Vision/scope document. The vision/scope document describes the project goalsand constraints. It outlines the solution being developed, the requirements thesolution will meet, and the approach that the team will take to complete the project.The vision/scope document is an early <strong>for</strong>m of the functional specification that isdeveloped during the Planning Phase. For more in<strong>for</strong>mation on creating yourvision/scope document, refer to the vision/scope template.● Project structure document. The project structure document defines the approachthe team will take to manage the project. It defines the team’s administrativestructure, standards, processes (such as version control and change control),project resources, and constraints. The document identifies the team leadresponsible <strong>for</strong> each MSF role.● Risk assessment document. The risk assessment document provides an initialidentification and analysis of risks associated with a project. This analysis includesmitigation and contingency plans to help the team manage specific risks. Refer tothe Risk Assessment template <strong>for</strong> more in<strong>for</strong>mation.Templates <strong>for</strong> each of these key deliverables are available in the Tools and Templatesfolder in the zip file download of this guidance athttp://go.microsoft.com/fwlink/?LinkId=45289.Table 2.1 lists the key activities that the team undertakes in the Envisioning Phase. Theresults of these activities are documented in this phase's deliverables.

14Envisioning PhaseTable 2.1: Major Tasks, Deliverables, and Primary OwnersTasks Project Deliverable Primary OwnerUnderstand the goals of the Vision/scope document Product Managementmigration project (businessand design)Create the problemVision/scope document Product ManagementstatementCreate the vision statement Vision/scope document Product ManagementDefine end user profiles Vision/scope document Product ManagementAssess the current situation Vision/scope document Program Management(high level)Identify high levelVision/scope document Product ManagementrequirementsDefine the project scope Vision/scope document Program ManagementDefine the solution concept Vision/scope document Program ManagementSet up a team Project structure document Program ManagementProduct ManagementDefine the project structure Project structure document Program ManagementAssess risk Risk assessment document Program ManagementNote This chapter provides in<strong>for</strong>mation about the essential tasks of the EnvisioningPhase <strong>for</strong> an <strong>Oracle</strong> on UNIX to SQL Server on Windows migration project. The chapteris not exhaustive. For a detailed description of all the activities and deliverables <strong>for</strong> theMSF Envisioning Phase, refer to the UNIX Migration Project <strong>Guide</strong> (UMPG) available athttp://go.microsoft.com/fwlink/?LinkId=19832.Understand the Goals of the Migration ProjectAn early, clear understanding of the goals of the migration project by the project team isimperative <strong>for</strong> its success. These high level goals are not defined by the project team;they are defined by the business managers and major stakeholders. The reasoning <strong>for</strong>reaching an early consensus on the goals includes:● The migration goals, once identified, are used to create a vision statement <strong>for</strong> themigration project. This vision statement is the key driver <strong>for</strong> all actions anddecisions made by the team during the course of the migration project.● The goals determine the aggregate skill set required by the project team tosuccessfully execute the migration project.● The project team uses these goals to scope specific requirements that, in turn,serve as the basis <strong>for</strong> detailed solution designs and plans.● The goals serve as the basis <strong>for</strong> reconciling conflicts and establishing priorities thatguide any trade-off decisions (schedule, features, resources, budgetaryrestrictions) that need to be made later in the project.The project goals can be classified as business goals and design goals. Both types ofgoals are described in detail in the following sections.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 15Define the Business GoalsBusiness goals are established either to take advantage of an opportunity or to solve aproblem in the current business. Each organization has business goals specific to them.For example, a business goal <strong>for</strong> one organization could be to “consolidate the ERPapplications across all worldwide units on one software plat<strong>for</strong>m after a merger withanother company,” while a different organization may have compliance with new federalregulations as its primary business goal. Because business goals can vary widely, thisguide does not provide a specific, comprehensive list of business goals. Yourorganization will have to determine the business goals specific to it. However, the twomost common business goals <strong>for</strong> IT projects are:● Reduce total cost of ownership (TCO) of the IT plat<strong>for</strong>m● Maximize return on investment (ROI)Because these two business goals are so common, they are discussed in more detailunder the following headings.Reduce TCO of IT Plat<strong>for</strong>mTCO of a system includes not only the price of purchasing software and hardware, butalso the cost of training users and supporting and maintaining the system. There<strong>for</strong>e,while evaluating the TCO of any system, there are several factors to consider.● Cost of hardware. Evaluate the cost of server hardware, networking equipmentsuch as hubs and routers, and other equipment. Also include facilities cost <strong>for</strong>hosting the hardware.● Cost of software. Evaluate the cost of all software including the operating systemand applications, such as database systems, developer tools, and managementsoftware.● Reliability of the system. If the system fails or crashes often, the support cost <strong>for</strong>such a system would increase.● Cost of system maintenance. System administration is single highest cost factor<strong>for</strong> any IT organization. Evaluate the staff strength needed and associated costs<strong>for</strong> maintaining the system.● Cost of supporting the users. Users may need extensive training and frequentsupport, significantly adding to the TCO.● Projected cost of the migration project itself. Factors such as availability ofskills in-house versus hiring external consultants will influence the project cost. Youwill be able to estimate these costs better after completing the Planning Phase.Microsoft offers several solutions to help reduce TCO.For example, Microsoft Visual Studio .NET provides an Integrated DevelopmentEnvironment (IDE) <strong>for</strong> rapid development of applications that reduces the cost ofdeveloping and upgrading applications. The Windows graphical user interface (GUI)environment provides an easy-to-use interface <strong>for</strong> Windows users. The Windowsstandard GUI and GUI-based management applications simplify server administrationand thus contribute to reducing support costs.For more in<strong>for</strong>mation about TCO on the Windows plat<strong>for</strong>m, refer tohttp://www.microsoft.com/business/reducecosts/efficiency/consolidate/tco.mspx.For customer case studies about reduced TCO on a Windows plat<strong>for</strong>m, refer tohttp://www.microsoft.com/business/reducecosts/efficiency/consolidate/casestudies.mspx#EBAA.

16Envisioning PhaseMaximize ROITCO is concerned with an organization’s bottom-line (cutting costs), and ROI is related tothe top line (increasing revenue). A lowered TCO and increased ROI scenario is theultimate goal of any migration project. To estimate the ROI due to the migration ef<strong>for</strong>t,you should take into account the following considerations:● Creation of new business opportunities. The migration may provide newtechnological capabilities and drive new business innovations that lead toincreased revenue.● Opportunities created by improved per<strong>for</strong>mance. For example, a fasterresponse time to online users on a Web site can drive more satisfied customers tothe site and increase profitability.● Total downtime required to complete the migration. System downtime canaffect revenue and should be minimized.● Reliability of the system. Unplanned system downtime can negatively affectproductivity and revenue.● Time to recover investment costs. The business needs to understand how longit expects to realize a return on the investment in the project.● Impact on user productivity due to the migration. If users are going to take along time to ramp up on the new technology, it can impact the near termproductivity and profitability of the organization. Productivity can also be affectedpositively by easing the integration between the database application and otheroffice software.● Managing risk. The organization needs to evaluate the risk of doing the project aswell as not doing the project. Not taking the risk may be the path of leastresistance, but it may deprive you of significant revenue opportunities. Proven bestpractices and processes can minimize risk and make the migration morepredictable. Several system integrators (SIs) offer service offerings that can greatlymitigate the risk. The SIs who are known to offer <strong>Oracle</strong> to SQL migrationofferings, as of publishing this solution, are listed in the "Set Up a Team" sectionlater in this chapter.Some of the questions that result from these considerations can be answered byanalysis. However, a proof-of-concept or a limited pilot exercise can help providequantifiable answers to these questions, including estimating application migration costsand determining the reliability of software. More in<strong>for</strong>mation is available in the "TechnicalProof of Concept" section of Chapter 3, "Planning Phase."Identify the Design GoalsDesign goals are similar to business goals in many ways. The difference is that designgoals focus more on the attributes of the solution and less on what the solution willaccomplish <strong>for</strong> the business. As with business goals, an organization's design goals areunique and specific to that organization. For example, one organization may determinethat “corporate data should be accessible from the mobile devices issued to companyemployees.” A different organization's primary design goal may be to “reduce the timeand level of ef<strong>for</strong>t required <strong>for</strong> a user to connect to the server and complete a task.” Thisguide does not provide a specific list of design goals. Your organization will have todetermine the design goals specific to it. However, the following list provides the six mostcommon and generic design goals <strong>for</strong> UNIX to Windows migration projects.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 17●●●●High availability and reliability. The solution should process requests withoutinterruption, even in the event of a failure. For more in<strong>for</strong>mation on Windowsreliability, refer to http://www.microsoft.com/mscorp/twc/reliability/default.mspxSQL Server allows <strong>for</strong> servers to be clustered into groups of connected nodes. Thesolution described in this guide provides high availability <strong>for</strong> business applications.If there is a failure of the operating system, hardware, or any planned upgradeevent on a single machine, SQL Server can be configured to fail over to anothernode, minimizing down time. For more in<strong>for</strong>mation about SQL Server clustering,refer to http://www.microsoft.com/resources/documentation/sql/2000/all/reskit/enus/part4/c1261.mspx.Robust security. In business, data security is vital. Launched under theTrustworthy Computing Initiative, Windows Server 2003 was designed with anemphasis on security.Many new features have been added, including support <strong>for</strong> strong authenticationprotocols such as Kerberos, 802.11x (WiFi) and Internet Protocol Security (IPSec).For more in<strong>for</strong>mation about Windows Server 2003 security, refer tohttp://www.microsoft.com/windowsserver2003/technologies/security.For more in<strong>for</strong>mation about SQL Server 2000 security, refer to the following threeresources:http://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/sp3sec01.mspxhttp://www.microsoft.com/sql/techinfo/administration/2000/security/default.asphttp://www.microsoft.com/sql/evaluation/features/security.aspHigh per<strong>for</strong>mance and scalability. The system should show an acceptable levelof per<strong>for</strong>mance even when the number of users increases.SQL Server 2000 can support multi-terabyte databases served to millions of users.This scalability is achieved by supporting scale up on symmetric multiprocessor(SMP) systems, allowing the installation of additional processors, memory, disksand networking to build a large single node. In addition, SQL Server supports scaleout, or allowing large databases to be split between a cluster of servers. Eachserver stores a portion of the database and assists in processing functions. Formore in<strong>for</strong>mation about Windows per<strong>for</strong>mance and scalability, refer to the followingtwo resources:http://www.microsoft.com/windowsserver2003/evaluation/per<strong>for</strong>mance/default.mspxhttp://www.microsoft.com/windowsserver2003/techinfo/serverroles/appserver/scale.mspxFor more in<strong>for</strong>mation about SQL Server per<strong>for</strong>mance and scalability, refer to thefollowing two resources:http://www.microsoft.com/technet/prodtechnol/sql/2000/plan/ssmsam.mspxhttp://www.microsoft.com/sql/evaluation/compare/benchmarks.aspEasy manageability. The system should provide easy ways <strong>for</strong> the administratorsto install, manage, and maintain the operating system, application software, andupdates. For more in<strong>for</strong>mation on management products from Microsoft, refer tohttp://www.microsoft.com/management/default.mspx.SQL Server provides a number of robust administration tools <strong>for</strong> managing data.Tools include graphic administration tools, task wizards, and command line utilities.For detailed in<strong>for</strong>mation about the SQL Server tool set, refer to the following tworesources:http://www.microsoft.com/technet/prodtechnol/sql/2000/books/c01ppcsq.mspx

18Envisioning Phase●●http://msdn.microsoft.com/library/default.asp?url=/library/enus/usetools/usetools_4ovn.aspConsolidation of servers. The new system should allow <strong>for</strong> the consolidation ofexisting databases into a small number of servers. If the existing solution is basedon older hardware, a migration presents an opportunity to consolidate to fewer andmore powerful servers.For more in<strong>for</strong>mation about Windows Server 2003 Datacenter Edition — theMicrosoft server operating system optimized <strong>for</strong> server consolidation — refer tohttp://www.microsoft.com/windowsserver2003/datacenter/default.mspx.Interoperability with the existing UNIX plat<strong>for</strong>m. The new system shouldintegrate with the existing applications and infrastructure on the UNIX plat<strong>for</strong>m. Formore in<strong>for</strong>mation about Windows interoperability with UNIX, refer tohttp://www.microsoft.com/sfu.For a detailed comparison of the system abilities of existing UNIX systems andWindows Server 2003 and SQL Server 2000, refer tohttp://go.microsoft.com/fwlink/?linkid=37907Create the Problem StatementA problem statement is usually a short narrative describing the specific issues that thebusiness hopes to address with the project. It relates primarily to the current state ofbusiness activities and is a direct result of the business goals or design goals not beingmet adequately. The more precisely the problem statement is recorded, the easier it willbe to measure the success of the project.Because the aim of the project is to solve a problem, the understanding of the problemdetermines the design of the solution. A good problem statement provides sufficientin<strong>for</strong>mation about the business problem <strong>for</strong> a new team member to use the problemstatement and the rest of the documentation to put the project into context.The following are some examples of problem statements that may be relevant in an<strong>Oracle</strong> on UNIX to SQL Server on Windows migration project:● Customer support cannot effectively process the high number of customer callsbecause of the time it takes <strong>for</strong> them to retrieve customer data from the existingcustomer database.● Product managers cannot make in<strong>for</strong>med decisions about sales promotionsbecause they do not have recent sales trends.Create the Vision StatementThe vision statement addresses the problem statement and establishes a common visionof the end state that can be shared among team members. While brief, this statementprovides a common starting point <strong>for</strong> future decisions throughout the rest of the project.A good vision statement has the following characteristics:● Specific. A vision statement should be specific and include the ideal state of thebusiness problem solution so that the end result is meaningful.● Measurable. By creating a vision statement that is measurable, the project teamcan determine the degree of success at the completion of the project.● Achievable. Given the resources, the time frame, and the skills of the teammembers, the vision statement should be achievable. An achievable andchallenging vision statement can motivate team members.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 19●●Relevant. The vision statement should relate to the business problem beingaddressed. If not, the project team might realize that they are solving the wrongproblem, or one that does not exist, and — in the process — lose sponsorship.Time-based. The vision statement should clearly indicate the estimated time frame<strong>for</strong> the delivery of the solution.The following two examples are vision statements <strong>for</strong> an <strong>Oracle</strong> on UNIX to SQL Serveron Windows migration project:● Be<strong>for</strong>e the end of the year, our customer support staff will be able to retrieve allcustomer data and account history within three seconds of the customer identifyinghimself or herself.● Be<strong>for</strong>e the start of the next fiscal year, our product managers will have access todaily sales reports from all the showrooms in the country.Define the User ProfilesUnderstanding the users <strong>for</strong> whom the solution is being developed is critical to theproject's success. To capture a clear description of each user, the team creates profilesof each user class. The process of profiling develops a set of user requirements. Thecombination of these user requirements with the business and design requirements willhelp to define the project scope later in the Envisioning Phase.In an <strong>Oracle</strong> on UNIX to SQL Server on Windows migration project, the most importantprofiles are that of the system managers and users of the migrated application. Considerthe following while profiling the user types:● Proficiency of the users in using Microsoft applications and the Windowsenvironment. Administrators largely use command line tools in the <strong>Oracle</strong>/UNIXworld. While Windows also provides some command line interfaces, Windowstools tend to be graphical user interfaces (GUIs). Users new to the Windowsenvironment may need training.● The type of tasks that the users will per<strong>for</strong>m on the new system.● Essential expectations of the end user from the current application interface thatwill have to be met in the new environment.● The language localization needs <strong>for</strong> the end users, if necessary. Consider the GUIas well as user documentation.● The physical location of the end users. Factors such as locations, number of usersat each location, and the bandwidth and usage of network links between the sitesshould be understood and documented.Assess the Current Situation (High Level)Organizations planning an <strong>Oracle</strong> on UNIX to SQL Server on Windows migration need toconsider the following five entities <strong>for</strong> a successful migration. While these entities areassessed in detail in the Planning Phase of the project, a high level preliminaryassessment is essential in the Envisioning Phase to evaluate the feasibility of the project.● ApplicationThis entity includes the target applications that are migration candidates. Whileassessing applications, the following questions should be asked:● Which are the specific applications that are to be migrated?● What languages are these applications written in?

20Envisioning Phase●●●If there are custom applications to be migrated, is the source code available?Are the developers of the application still a part of the team?Do the applications to be migrated interoperate with other applications orsystems?●●●●DatabaseThis entity includes the <strong>Oracle</strong> databases that need to be migrated to SQL Server.The following are some of the high level questions you need to ask:●●●●Do your existing databases implement specialized features of <strong>Oracle</strong> or anyother third-party customizations to provide additional database features?Are the databases that need to be migrated shared by multiple applications?What are the sizes of the databases being migrated?What is the user population of the databases?Application infrastructureThis entity includes server and network-related resources, such as compute nodes,storage, file systems, routers, firewalls, hubs, and so on. The following are some ofthe questions you need to ask to assess the current state:● Do you already have an existing infrastructure based on Windows that can bereadily used or expanded, or do you have to set up the infrastructure fromscratch?● What are the other external systems, such as those of your partners or clients,that would be impacted by the migration?Microsoft provides a standardized infrastructure architecture named WindowsServer System Reference Architecture (WSSRA). WSSRA provides lab and realworld tested, architectural blueprints and proven best practices to design andimplement enterprise infrastructure solutions with minimal risk and cost. Theguidance addresses infrastructure issues including availability, security, scalability,and manageability of the plat<strong>for</strong>m in a fully integrated fashion. For detailedin<strong>for</strong>mation on WSSRA, refer tohttp://www.microsoft.com/windowsserversystem/overview/referencearchitecture.mspx.Development environmentThis entity includes software construction environments such as the UNIX makeenvironment, developer tools, and so on. Migration of the database and data canbe achieved by using tools bundled with <strong>Oracle</strong> and SQL Server, such asSQL*Plus, Enterprise Manager, and Query Analyzer. Microsoft offers a set of toolscalled SQL Server Migration Assistant <strong>for</strong> migrating <strong>Oracle</strong> databases toSQL Server.Questions to ask while assessing the development environment include:● What is the software construction environment that you have to build the UNIXapplications? A commonly used software construction mechanism is the use ofmakefiles. For detailed process and technical guidance on using a makebasedbuild environment to build Windows executables, refer tohttp://go.microsoft.com/fwlink/?LinkId=22225● Are the required licenses <strong>for</strong> the appropriate SQL Server edition available?● What are the server, storage, and network resources to support thedevelopment and testing activities?Existing documentation

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 21This entity includes end user documentation, requirements analysis, functionalspecifications, design documents, and so on. The existing documentation shouldbe scrutinized as part of the task of assessing your current environment. This issomething that is often overlooked. Existing design documentation is a valuableresource <strong>for</strong> building project documents and plans, especially when a large portionof the existing functionality is carried over to the new solution. Developing testplans and test cases <strong>for</strong> the new application based upon existing documentation isespecially useful. Modifications to existing documentation are almost certainlyneeded to support the migrated solution. One problem often encountered is thatthe existing documentation is incorrect or insufficient, which may <strong>for</strong>ce themigration project to absorb the ef<strong>for</strong>t of bringing it up to date.These are some of the questions that you need to ask:● Are the original requirements <strong>for</strong> each of the applications to be migratedavailable?● Are database and application design (high level as well as detailed) documentsavailable?● Are the logical and physical data models available <strong>for</strong> all databases to bemigrated?● Is documentation <strong>for</strong> the application code maintained?● Are user manuals available <strong>for</strong> client applications?● Are training documents available <strong>for</strong> support, end users, and operationspersonnel?●Application usersUser accounts that exist in the UNIX domain need to be migrated or recreated inthe Windows-based domain along with the necessary permissions <strong>for</strong> users to startusing the application on the Windows domain. Ask the following questions:● What security services are in use (examples include local, Kerberos, NIS,NIS+, and LDAP)?● What is the authentication method in use (examples include password, digitalcertificate, and so on)?● What authority does the user have on the system?● How is authorization implemented?● What activities of the users are audited?● Are users required to use secure communication methods such as SSH?● Are application users authenticated by the operating system as well as by thedatabase?For prescriptive guidance on how to enable Windows Server 2003 to be used <strong>for</strong>authentication and as an identity store within Windows and UNIX environments,refer to http://go.microsoft.com/fwlink/?LinkId=23120.Note The primary purpose of this solution is to provide guidance on migrating theapplications and databases from an <strong>Oracle</strong> on UNIX environment to a SQL Server onWindows environment. The discussions about migrating the infrastructure, developmentenvironment, user accounts, and documentation are, there<strong>for</strong>e, limited in this solution.The discussions have been included to provide readers a holistic perspective of themigration. Pointers to other resources that provide more in<strong>for</strong>mation, includingprescriptive guidance, are provided when relevant.

22Envisioning PhaseFigure 2.1 represents the primary entities involved in an <strong>Oracle</strong> on UNIX to SQL Serveron Windows migration. To reiterate: this guide provides prescriptive guidance <strong>for</strong>migrating the application, database, and application infrastructure entities only.In<strong>for</strong>mation about the other entities is available from the sources cited earlier.Figure 2.1Primary Migration EntitiesCapture High Level RequirementsAn important task in the Envisioning Phase is to document the high-level business, user,and design requirements. These requirements are refined further in the conceptualdesign stage of the Planning Phase (discussed in Chapter 3, "Planning Phase").A common way of gathering and analyzing in<strong>for</strong>mation is through developing use-casesand building usage scenarios to document the business processes and userrequirements. While use cases describe the high level interactions between an individualand the system, usage scenarios provide additional in<strong>for</strong>mation about the activities andtask sequences that constitute a process.A detailed discussion of use-case analysis is out of scope of this solution. Please refer tothe following resource <strong>for</strong> additional guidance: Advanced Use Case Modeling (Armourand Miller, 2000).Define the Project ScopeOne of the critical factors in the success of a project is clearly defining the scope of theproject. Scope defines what will be and what will not be included in the project. Thescope uses the high level requirements gathered earlier in the Envisioning Phase andincorporates the constraints imposed on the project by resources, schedule, budget, andother limiting factors. A good way of scoping is to address use cases and usagescenarios that impact the business the most.As with the business and design goals, the scope <strong>for</strong> projects is organization-specific,and you will need to determine the scope <strong>for</strong> your project and document it in the

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 23vision/scope document. However, when producing the scope <strong>for</strong> your <strong>Oracle</strong> on UNIX toSQL Server on Windows migration project, some general guidelines should be followed:●●●●●●●Consider a multiphase approach to the migration. In the first phase, considermigrating only the database and reconnect the UNIX applications to connect toSQL Server. Limiting the scope <strong>for</strong> each phase of the migration increases yourability to monitor and measure the migration project's success.Consider migrating the portable applications first. These include applicationswritten using Java, Perl, PHP, and Python. Portable applications can usually beported or configured to interoperate with relative ease, and this helps build userand management confidence.<strong>Oracle</strong> Forms and Pro*C applications are the hardest to migrate because theyhave to be rewritten; per<strong>for</strong>m them in a later phase, if possible.The migration of code present in the database in the <strong>for</strong>m of triggers, functions,stored procedures, and packages impacts the migration of applications that aredependent on them. As a result, these have to be migrated first.Databases using advanced <strong>Oracle</strong> functionality, such as advanced queuing, Javapackages, objects, and so on are more difficult to migrate, and a proof-of-conceptshould be created to verify the solution.Smaller databases with less stringent requirements on per<strong>for</strong>mance and availabilityshould be migrated be<strong>for</strong>e attempting larger ones.To reduce the complexity, migration at the schema level should be consideredwhere feasible instead of entire databases.Define the <strong>Solution</strong> ConceptThe solution concept outlines the high level approach the team will take to meet the goalsof the project and provides the basis <strong>for</strong> proceeding to the Planning Phase. Thisapproach includes the assessment of technologies, development, test, quality assurance,training, deployment, release, operations and so on. These approaches can bedeveloped into full-fledged plans in the Planning Phase. Because the solution conceptfocuses on the concepts and not the details, it is not very technical.The solution concept also includes a high-level solution design strategy <strong>for</strong> all thesoftware and hardware components of the system. Because the primary focus of thissolution is migrating the <strong>Oracle</strong> databases and associated applications to SQL Server onWindows, the rest of this section discusses only solution design strategies <strong>for</strong> thedatabase and applications.Application and Database Migration <strong>Solution</strong> DesignStrategyFor the purposes of explanation, the application and database ecosystem can be viewedin terms of three components:● Application. This component includes applications written in a variety ofprogramming languages, including <strong>Oracle</strong> Forms, Perl, Python, and so on.● Connectivity interface. This is the intermediate tier between the application and thedatabase. The connectivity tier is also referred to as the application programminginterface (API). This layer facilitates the communication between the applicationand the database. <strong>Oracle</strong> and SQL Server support different connectivity interfaces,some proprietary and some standard. <strong>Oracle</strong> Call Interface (OCI) is an example ofa proprietary interface <strong>for</strong> an application to communicate with <strong>Oracle</strong>. Object

24Envisioning Phase●Database Connectivity (ODBC) is an example of a standards-based interface. Theavailable API also differs from UNIX to Windows.Database. The database tier consists of the database management system andthe objects that store and facilitate access to the data in the database.The relationship between these three components is shown in Figure 2.2. Theconnectivity interface binds the application to the database and allows in<strong>for</strong>mation topass between them.Figure 2.2Application, database, and connectivity tiersOnce the database is migrated from <strong>Oracle</strong> to SQL Server, there are four differentapproaches to connect the application to the SQL Server database using an appropriateconnectivity layer.1. InteroperationThe application components remain on the UNIX plat<strong>for</strong>m.2. Port or rewrite application to the .NET plat<strong>for</strong>mThe.NET framework is the next generation plat<strong>for</strong>m from Microsoft <strong>for</strong> building,deploying, and running Windows applications. It provides a standards-based, multilanguageenvironment <strong>for</strong> integrating existing investments with next-generationapplications and services.3. Port or rewrite application to Win32 plat<strong>for</strong>mThe Win32 API is one of the primary programming interfaces to the Windowsoperating system family, including Windows 2003. The Win32 API providesfunctions <strong>for</strong> processes, memory management, security, windowing, and graphics.4. Quick port: port application to the Windows Services <strong>for</strong> UNIX 3.5 plat<strong>for</strong>mPort applications to an environment on Windows named Interix, which is similar toUNIX. Interix is a complete, POSIX-compliant development environment that istightly integrated with the Windows kernel. It is a part of the MicrosoftWindows Services <strong>for</strong> UNIX 3.5 product suite from Microsoft.Each of these four options constitutes a separate design strategy <strong>for</strong> your migrationproject, and each of the four is discussed in more detail under the following headings.One, some, or all of these solution design strategies will <strong>for</strong>m the basis of the solutionconcept you will produce as a part of completing the Envisioning Phase. Even when thegoal is to standardize on the Windows plat<strong>for</strong>m, some of these strategies may beemployed as intermediary steps in a multi-phased migration. This solution concept —documented in the vision/scope document — will be used to develop detailed plansduring the Planning Phase and code during the Developing Phase.Note Due to the complexities inherent in a migration project, it may not be possible toimmediately select a migration strategy. Proof-of-concept testing may need to occurbe<strong>for</strong>e the design strategy is decided upon.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 25<strong>Solution</strong> Design Strategy A: InteroperabilityIn this strategy, the applications remain on the UNIX plat<strong>for</strong>m while the database alone ismigrated from <strong>Oracle</strong> to SQL Server.Interoperation is preferred in the following situations:●●●●The migration ef<strong>for</strong>t and risks need to be minimized at the expense of not beingable to fully realize the benefits of migrating the application to Windows.A multiphased approach <strong>for</strong> migration is more appropriate. The first phase ofmigration could involve migrating the database only, and later phases could focuson migrating the applications.The needs served by the application are static; the evolution of the application isnot a business or design goal of the project.Maintaining a tight or complex integration of UNIX applications with other servicesis required.Interoperation is not recommended in the following situations:●●●●●The cost of maintaining two environments is prohibitive.The goals of the project include changing the application to take advantage of thegreater business value of Windows technologies.Components being on two different plat<strong>for</strong>ms do not produce acceptableper<strong>for</strong>mance or service levels.The required measure of security cannot be achieved because of disparatetechnologies.When the interoperation is complex and requires huge ef<strong>for</strong>t in development andimplementation as compared to employing one of the other methods.<strong>Solution</strong> Design Strategy B: Port or Rewrite to .NET FrameworkWhen migrating an application to the .NET framework, there are two different options.One is to per<strong>for</strong>m a full port of the application, and the other is to rewrite the applicationusing the .NET application programming interfaces (APIs).A full port is defined as the capability to execute the application in the Windowsenvironment in its native <strong>for</strong>m. Applications written using languages such as Java, Perl,PHP, and Python, which are available on both the UNIX and Windows plat<strong>for</strong>ms, cantake advantage of a full port. In most cases, SQL Server database drivers are available<strong>for</strong> the specific application languages. A full port requires minimum changes to be done tothe source code, and a full port uses standard libraries and utilities that exist on theWindows plat<strong>for</strong>m. New documentation and user training is not required in the case of afull port because the business logic and the user interface remain the same.A full port to the .NET framework is preferred in the following situations:● The programming environment in which the application was written is fullysupported in the .NET framework.● Appropriate .NET database drivers are available and support all the function callsmade in the application code.● Rewriting an application consumes too much time and increases cost prohibitively.● When ported into the .NET framework, the application successfully interacts withother applications.A rewrite of the application would be required when there are no equivalents on the .NETplat<strong>for</strong>m <strong>for</strong> the language in use. An example of this would be applications based on

26Envisioning Phase<strong>Oracle</strong> Forms. The best option in this case would be to rewrite the application onWindows using Visual Basic .NET.A rewrite of the application is preferred in the following situations:● The cost and complexity of porting is prohibitively high. It may be easier to recreatethe application rapidly using Visual Basic.NET, rather than porting the application.● The business logic is likely to change significantly in the new environment, whichwould limit the amount of code reused from the source plat<strong>for</strong>m.● The application requires new features and code that is specific to the Windowsenvironment.● Tight integration with Windows features is required in the new application.● The best possible integration with other Windows-based applications is required.● A port is not possible either because the language is not supported or API libraries<strong>for</strong> SQL Server do not exist.Potentially, rewriting an application can be challenging. It can be a time-consuming, risky,and costly option. The risk inherent in a rewrite is that the business logic or an importantfunctionality is changed while rewriting the code. Careful testing and stabilizing of therewritten application needs to be conducted to ensure proper business logic andfunctionality.When porting or rewriting to Windows, migration to the .NET plat<strong>for</strong>m is preferred. .NETtechnology provides the ability to build, deploy, manage, and use connected, securityenhancedsolutions with Web services. For more in<strong>for</strong>mation about the .NET plat<strong>for</strong>mand its key capabilities, refer to the following two resources:http://www.microsoft.com/net/basics/http://msdn.microsoft.com/netframework/programming/fundamentals/default.aspxThere are situations when moving to .NET may not be feasible. For instance, at the timethat this guide was published no production-ready implementations of Python on the.NET framework existed. However, this technology is currently available in a beta <strong>for</strong>mat,and investigation of current technologies is recommended.<strong>Solution</strong> Design Strategy C: Port or Rewrite to Win32The.NET Framework offers the next generation of applications and services. Migration tothe Win32 plat<strong>for</strong>m should be considered when migration to .NET is not technicallyfeasible <strong>for</strong> your organization. As with strategy B, two migration options are availablewhen moving to a Win32-based plat<strong>for</strong>m. The first is to per<strong>for</strong>m a full port of theapplication, and the other is to rewrite the application using the Win32 APIs. The rationale<strong>for</strong> deciding whether to port or rewrite the application to function with Win32 is the sameas the rationale <strong>for</strong> using .NET. Please refer to the description in the "<strong>Solution</strong> DesignStrategy B: Port or Rewrite to .NET Framework" section <strong>for</strong> more details.<strong>Solution</strong> Design Strategy D: Quick Port by <strong>Migrating</strong> toWindows Services <strong>for</strong> UNIXOne of the quickest migration paths possible is to port the code directly toWindows Services <strong>for</strong> UNIX. Windows Services <strong>for</strong> UNIX includes Microsoft Interix, whichprovides a UNIX environment that runs on top of the Windows kernel. Interix allowsnative UNIX applications and scripts to work alongside Windows applications. The bestway to view Interix is to understand it as a POSIX-compliant version of UNIX built on topof the Windows kernel. It is not an emulation of a UNIX environment on the WindowsAPIs. Migration using Windows Services <strong>for</strong> UNIX involves obtaining the source code,

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 27installing it in the Interix development environment, modifying the configuration scriptsand makefiles, and recompiling the application. This strategy is referred to as a quickport.The ported application may be successful immediately, or it may require modifications tothe configuration scripts or makefiles to account <strong>for</strong> the new hardware plat<strong>for</strong>m, the targetoperating systems, and local configuration in<strong>for</strong>mation. A detailed assessment of theapplication has to be conducted to inventory the various APIs and utilities in use. Thesupport <strong>for</strong> these in the Windows Services <strong>for</strong> UNIX environment has to be verified.Extensive testing of the application is essential after the port to ensure that all featureshave been migrated successfully.A quick port is preferred in the following situations:● A port <strong>for</strong> the language the application was written in does not exist in .NET orWin32. An example application is X Windows.● Application investments on the UNIX plat<strong>for</strong>m need to be reused. Interix canoptimize your investments in UNIX applications by reusing code. New functionalityand value can be added to your existing UNIX applications by integrating the UNIXcode with .NET or Win32 functionality.● It is too expensive and time-consuming to do a full port or complete rewrite of theapplication.● A large set of UNIX scripts need to be ported. Interix allows you to get the most outof existing UNIX network administrator tools and skill sets. It provides more than300 UNIX utilities, and it provides shells and scripting languages (including Perl)that enable you to run existing shell scripts with little or no change on Windows.A quick port is not recommended in the following situations:● A port of the application is available in Win32 or .NET.● You can af<strong>for</strong>d the rewrite or port to Win32 or .NET and wants to tightly integratethe application with other Windows technologies.● You want to significantly evolve the application by using the capabilities of theWindows environment.● A quick port requires huge ef<strong>for</strong>t in development and implementation as comparedto employing one of the other methods. For example, when the required librariesavailable on the original UNIX plat<strong>for</strong>m are not available on Interix.Most UNIX database environments use scripts to support databases and clientapplications. You should evaluate the importance of the services that these scriptsper<strong>for</strong>m. <strong>Migrating</strong> the scripts to Windows Services <strong>for</strong> UNIX is an option; however,scripts that make use of <strong>Oracle</strong> utility programs must be modified to use suitablereplacements <strong>for</strong> SQL Server.Using Windows Services <strong>for</strong> UNIX, organizations can rapidly consolidate diverseplat<strong>for</strong>ms, maximizing their previous investments in UNIX infrastructure, applications, andknowledge while capitalizing on Windows innovation. Moreover,Windows Services <strong>for</strong> UNIX provides a full range of supported and fully integrated, crossplat<strong>for</strong>mnetwork services <strong>for</strong> blending Windows and UNIX networks.For a detailed discussion of Windows Services <strong>for</strong> UNIX in migration projects, refer to theUNIX Application Migration <strong>Guide</strong> available athttp://go.microsoft.com/fwlink/?LinkId=30832Windows Services <strong>for</strong> UNIX 3.5 is available as a complimentary download from Microsoft<strong>for</strong> Windows Server 2003, Windows® XP Professional, and Windows® 2000.Some Windows Services <strong>for</strong> UNIX 3.5 features include:

28Envisioning Phase●●●It is designed to work well with other major UNIX plat<strong>for</strong>ms and versions. It hasbeen tested specifically with Sun Solaris 7 and 8, HP-UX 11i, AIX 5L 5.2, and RedHat Linux 8.0.It includes version 5.6 of the ActiveState Perl distribution <strong>for</strong> native Windowsscripting and Perl 5.6.1 <strong>for</strong> scripting in the Interix environment.It includes more than 300 UNIX utilities and tools that per<strong>for</strong>m on UNIX andWindows systems in a similar manner. In addition, Windows Services <strong>for</strong> UNIX 3.5also contains a Software Development Kit (SDK) that supports more than 1,900UNIX APIs and migration tools, such as make, rcs, yacc, lex, cc, c89, nm, strip,and gbd, as well as the gcc, g++, and g77 compilers.More in<strong>for</strong>mation about Windows Services <strong>for</strong> UNIX is available from the following tworesources:http://www.microsoft.com/windows/sfu/productinfo/overview/default.asphttp://www.microsoft.com/windows/sfu/Migration Strategy ScenariosTables 2.2 through 2.5 show the migration opportunities <strong>for</strong> several scenarios of thesource UNIX environment. Each scenario is a combination of the three components ofdatabase, application, and connectivity (API). The first column of the tables representsthe current state in the UNIX environment, and the third column shows the migrationpossibilities <strong>for</strong> each of the migration strategies: interoperate, port or rewrite to the .NETFramework, port or rewrite to Win32, and port to Windows Services <strong>for</strong> UNIX.Table 2.2: Application Interoperation Strategy<strong>Oracle</strong>/UNIXlanguagePHPAPI<strong>Oracle</strong> or OCI8 orODBCInteroperate SQLServer/UNIXlanguagePHPAPIMS SQL Server orODBCPro*C OCI <strong>Solution</strong> not availableor feasible<strong>Oracle</strong> Forms Forms C or JDAPI <strong>Solution</strong> not availableor feasiblePerl <strong>Oracle</strong> or ODBC Perl ODBC or SybasePython <strong>Oracle</strong> or ODBC Python ODBCJava JDBC Java JDBC

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 29Table 2.3: Application Port to Windows Services <strong>for</strong> UNIX Strategy<strong>Oracle</strong>/UNIXlanguagePHPAPI<strong>Oracle</strong> or OCI8 orODBCPort SQLServer/WindowsServices <strong>for</strong> UNIXlanguagePHPPro*C OCI <strong>Solution</strong> not availableor feasible<strong>Oracle</strong> Forms Forms C or JDAPI <strong>Solution</strong> not availableor feasibleAPIMS SQL Server orODBCPerl <strong>Oracle</strong> or ODBC Perl ODBC or SybasePython <strong>Oracle</strong> or ODBC Python ODBCJava JDBC Java JDBCTable 2.4: Application Port or Rewrite to Win32 Strategy<strong>Oracle</strong>/UNIXlanguagePHPAPI<strong>Oracle</strong> or OCI8 orODBCPort/rewrite SQLServer/WIN32languagePHPAPIMS SQL Server orODBCPro*C OCI VB ODBC or ADO<strong>Oracle</strong> Forms Forms C or JDAPI VB ODBC or ADOPerl <strong>Oracle</strong> or ODBC Perl ODBC or ADOPython <strong>Oracle</strong> or ODBC Python ODBCJava JDBC Java JDBCTable 2.5: Application Port or Rewrite to .NET Strategy<strong>Oracle</strong>/UNIXlanguagePHPAPI<strong>Oracle</strong> or OCI8 orODBCPort/rewrite SQLServer/.NETlanguage<strong>Solution</strong> not availableor feasiblePro*C OCI VB.NET ODBC or ADO.NET<strong>Oracle</strong> Forms Forms C or JDAPI VB.NET ODBC or ADO.NETPerl <strong>Oracle</strong> or ODBC Perl PerlNETPython <strong>Oracle</strong> or ODBC <strong>Solution</strong> not availableor feasibleJava JDBC <strong>Solution</strong> not availableor feasibleAPI

30Envisioning PhaseOptimal StrategyThe factors that need to be considered while deciding a migration strategy are:●●●●Business needs. The migration strategy should meet the present and futureneeds of the organization.For example, an organization may need to open its existing application to externalusers. Security needs to be implemented <strong>for</strong> the external users. The organizationmay select the rewrite strategy.Technical feasibility. <strong>Migrating</strong> <strong>Oracle</strong> Forms to the Windows plat<strong>for</strong>m may not betechnically feasible. If the new features warrant a lot of change to the currentapplication, the organization may opt to select rewriting as a strategy.Time. The time frame within which the migration has to be planned, developed,tested, and deployed needs to be decided. In addition, the actual time taken in themigration needs to be minimized to reduce the business risk.For example, an organization may plan to provide access to its application to theexternal users within three months. A quick port to the Windows Services <strong>for</strong> UNIXplat<strong>for</strong>m may be the best option.Budget. The budget available needs to be planned. According to the moneyavailable, the infrastructure, human resources, and cost need to be planned.For example, the direct cost of porting may be lower than the cost of a rewrite.Also, porting an application minimizes the cost of training, as the same applicationis used in the new environment. The indirect cost; such as cost of maintenance,testing, and retraining, will also be lower.Set Up a TeamTo trans<strong>for</strong>m overall business and design goals into a clear vision <strong>for</strong> the project, anorganization needs to assemble a multidisciplinary team, based on MSF roles, and withdefined skill sets appropriate to the project. These roles are Product Management,Program Management, Development, Test, User Experience, and Release Management.Once assembled, this team defines the vision and scope that together provide a cleardirection <strong>for</strong> the project and set expectations within the organization. During theEnvisioning Phase, it is likely that only the lead person or persons <strong>for</strong> each team role willbe determined. During the Planning Phase, the entire team should be assembled if it isnecessary <strong>for</strong> your organization to staff each role with more than one person. Morein<strong>for</strong>mation about the MSF Team Model is available in the UMPG.Table 2.6 lists each role with its goal and identifies its key functional areas and projectresponsibilities <strong>for</strong> an <strong>Oracle</strong> on UNIX to SQL Server on Windows migration project.Table 2.6: Project Requirements and Responsibilities by TaskRole Project responsibilities and tasks Knowledge and skillrequirementsProductManagementRole* Ensure that the team addressesbusiness goals and customerrequirements* Manage communications, launchplanning, and feedback with customers(both internal and external)Understanding of theorganization's businesspriorities and goalsProgram * Drive solution design * Project management skills

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 31Role Project responsibilities and tasks Knowledge and skillrequirementsManagementRoleDevelopmentRoleDevelopmentFunctionalTeam #1(Database)* Manage projects to meet budget andschedule* Manage scope and track progress* Provide process leadershipIt is recommended that two teams becreated <strong>for</strong> the Development Role. Onedevelopment team should focus onmigrating the database, providingdatabase administration and support.The second development team shouldfocus on migrating the application.* Ensure that requirements of theWindows environment are met <strong>for</strong> themigrated database (<strong>for</strong> example, OSsupport <strong>for</strong> amount of memoryrequired).* Identify and provide access to shelland other scripts that are used tosupport the database being migrated.* Migrate user accounts and verifiy thatthey have been migrated correctly.* Install DBMS software and databaseapplications on servers.* Create database in SQL Server andmigrate data from <strong>Oracle</strong>.* Identify the time and order in whichthe shell scripts are invoked.* Design and implement the appropriatesecurity model <strong>for</strong> migrated databases,based on analysis of application anddatabase.* Identify and resolve issues associatedwith Windows security and connectivity.* Validate that the chosen securityconfiguration provides at least the samesecurity levels as the existingconfiguration.* Apply appropriate permissions at thedatabase object level.* Work with test groups to build testenvironment.* Work with client developmentfunctional team on issues related toconnectivity between database andapplication* Communication skills* Adequate knowledge of UNIXand Windows environmentsand of <strong>Oracle</strong> and SQL Serverdatabases to drive solutiondesign* Knowledge of securityconfiguration <strong>for</strong> current <strong>Oracle</strong>database and applicationsrunning on UNIX.* Knowledge of shell and otherscripts used to support the<strong>Oracle</strong> database.* Knowledge of cron jobs,including times and the orderin which scripts are run.* Understanding of security,connectivity, software, anddatabase installation issues inthe Windows environment.* Understanding of both theWindows and UNIXenvironment.* Understanding of NetworkLibrary <strong>Oracle</strong> SQL*Net, Net8,and TCP/IP.* Understanding of the <strong>Oracle</strong>schema, tables, views, storedprocedures and triggers.*Knowledge of SQL Serverand ability to per<strong>for</strong>m all thesetasks in a Windowsenvironment

32Envisioning PhaseRole Project responsibilities and tasks Knowledge and skillrequirementsDevelopmentFunctionalTeam #2(Application)UserExperienceRoleTest Role* Participate in assessment activities <strong>for</strong>client applications.* Identify and articulate securityrequirements <strong>for</strong> client applications.* Retarget or migrate existing clientapplications.* Work with test team to ensurerequirements are met and defects arereduced.* Work with database team on issuesrelated to connectivity or otherdatabase-related problems.* Manage process of gathering,analyzing, and prioritizing userrequirements.* Help develop usage scenarios anduse cases.* Provide feedback on the solutiondesign.* Drive the creation of user trainingmaterials.* Participate in data gathering relevantto Test during all phases of the project.* Design and develop the testenvironment in conjunction with theDevelopment functional teams <strong>for</strong>database and client migrations.* Maintain ownership of the testenvironment.* Design, create the specification <strong>for</strong>,and refine the test plan and the useracceptance test plan.* Implement and validate the migrationtest plan.Implement test cases.* Knowledge of <strong>Oracle</strong> clientapplications and their securityrequirements.* Proficiency in either Perl,Python, PHP, Java, VisualBasic.NET, Windows Services<strong>for</strong> UNIX, or Windows.* Experience with technologies<strong>for</strong> application interoperationwith SQL Server such asFreeTDS.* Understanding of storedprocedures, database logic,and application logic.* Understanding of connectivityissues with database.* Understanding of theapplications being migrated.* Experience in developingusage scenarios and usecases.* Understanding of trainingprinciples.* Understanding of the UNIXand Windows operatingsystems (including WindowsServices <strong>for</strong> UNIX, ifappropriate).* Expertise with <strong>Oracle</strong>databases, application andclient development.* Experience withinteroperation between UNIXand Windows.* Understanding of tiereddatabase systems inhomogeneous andheterogeneous environments.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 33Role Project responsibilities and tasks Knowledge and skillrequirementsReleaseManagement* Act as primary advocate betweenproject development and operationsgroups.* Manage tool selection <strong>for</strong> releaseactivities and drive optimizingautomation.* Set operations criteria <strong>for</strong> release toproduction.* Participate in design, focusing onmanageability, supportability, and indeployment.* Drive training <strong>for</strong> operations.* Drive and set up <strong>for</strong> pilot deployments.* Plan and manage solution deploymentinto production.* Ensure that stabilizationmeasurements meet acceptancecriteria.* Understanding of standardoperational procedures in theWindows environment.* Understanding ofapplications being migrated.* Management andcommunication skills.Special Considerations <strong>for</strong> Setting Up Your Migration TeamAn <strong>Oracle</strong> on UNIX to SQL Server on Windows migration project can present someunique issues <strong>for</strong> staffing your project team. Keep the following considerations in mindwhen staffing your project team:● It is relatively easy to find technical staff with a deep knowledge of <strong>Oracle</strong> andUNIX or SQL and Windows, but it is not easy to find technical staff that has a deepunderstanding of all of these areas. Migration involves creating a metaphoricalbridge between the two environments. Make sure you have a senior architect onthe team who understands both worlds deeply enough to engineer the bridge'screation. If the skill is not available in-house, consider finding a consultant or aconsulting organization with experience in this <strong>for</strong>m of migration. The consultingorganizations often offer services to complete these migration projects end-to-end.It may be possible <strong>for</strong> you to successfully implement the migration with loweredrisk and reduced cost by engaging a consulting organization. For more in<strong>for</strong>mationabout Microsoft partners that offer <strong>Oracle</strong> to SQL Server migration services, referto http://www.microsoft.com/sql/partners/migration.asp● Ensure that the hardware and infrastructure experts from the Development Roleand Test Role are actively engaged during the Envisioning Phase. The hardwareon which databases and applications are run is commonly overlooked until later inthe project life cycle than it should be. Involving the experts early in the project willhelp in<strong>for</strong>m more accurate estimates regarding budget, time, and resources.● The Test Role should include, if possible, team members who have worked withthe application being migrated. Their experience will help them write better testcases.● The User Experience Role should include, if possible, team members who haveworked with the application in the UNIX environment. They should have a goodunderstanding of the application's user interface so that they will be able to defineand provide the training required <strong>for</strong> end users after the application migration.

34Envisioning Phase●●●●●Consider including in the Test Role team members who have the expertise to testthe security of the migrated environment. The security of the migrated applicationis often overlooked in migration projects.Migration projects are often undertaken using existing technical staff who haveday-to-day responsibilities which impact their availability. Resources should beproperly planned and allocated to the project to avoid such impact.Technical staff that has experience with the current application and databaseshould be involved in the project from design to deployment. Any required trainingshould be provided to improve their utility in the migration.Security, hardware, and infrastructure experts from Operations should also beinvolved in the Envisioning Phase because they can provide valuable advice aboutthe technical availability, costs, and the capabilities of the organization.Because moving from <strong>Oracle</strong> on UNIX to SQL Server on Windows is a majorparadigm shift, it could impact the employment and careers of existing personnel.This issue should be considered when <strong>for</strong>ming the team and carrying out themigration. Change is often inevitable and should be perceived as a way to expandand develop skills.Define the Project StructureThe project structure defines how the team manages and supports the project anddescribes the administrative structure <strong>for</strong> the project team going into the subsequentproject phases.The main function of the project structure is to define standards the team will use duringthe project. These include communication standards, documentation standards, andchange control procedure standards. Program Management takes the lead in defining theproject structure.Refer to the UNIX Migration Project <strong>Guide</strong> <strong>for</strong> detailed in<strong>for</strong>mation about project structure.Use the Project Structure document template to assist you in defining and recording theproject structure and protocols <strong>for</strong> the project team. This template is available in theToolsand Templates folder in the zip file download of this guidance athttp://go.microsoft.com/fwlink/?LinkId=45289.Define Project CommunicationsProgram Management should use the project structure to define standards <strong>for</strong> teammembers to communicate with one another. Among these standards can be a definitionof the reporting structure under which team members operate, procedures to elevateproject issues, regular mandated status meetings, and any other project-specificcommunication standards that need to be defined during the Envisioning Phase.The document may also include e-mail names, aliases, telephone lists, mail addresses,server share names, directory structures, and other in<strong>for</strong>mation critical to teamorganization. Consider establishing a team collaboration environment wherecommunication can occur and progress be monitored and updated as necessary. Thefollowing list of factors needs to be considered <strong>for</strong> most <strong>Oracle</strong> on UNIX to SQL Serveron Windows migration projects.● The project team will likely include members from the UNIX domain of the ITdepartment as well as the Windows domain. There are often work-based culturaldifferences between members of these two domains. The Program Managementrole should ensure that this potential difference is identified and extra attention ispaid to ensure clear communication between the members of the two domains.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 35●●Similarly, the communication tools used by the UNIX and Windows users are oftenvery different. For example, Windows users use the calendaring features ofOutlook extensively <strong>for</strong> team communication. The UNIX users may be accustomedto a different set of tools or clients.Different geographical locations and different cultural backgrounds of teammembers involved in the migration ef<strong>for</strong>t can cause communication issues. Extraattention is required to make sure that there is clear communication between allteam members.Determine secure methods to share in<strong>for</strong>mation about the project among the teammembers. If your team comprises consultants and in-house employees, there maybe corporate policies about what in<strong>for</strong>mation can be shared with outsideconsultants.Define Change ControlChange control standards and tools help to manage both project documents andcomponents of the solution that are subject to revision or iteration. The requirementsshould be clearly defined in the project structure. General in<strong>for</strong>mation about changecontrol is available in the UMPG.Migration projects have an additional source of change that is not obvious but must bemanaged: the initial state of the technology being migrated. This could be source code <strong>for</strong>applications, hardware and software configuration, and versions of application software.Although the initial state can be baselined when the migration project is started,operational needs may require changes to that configuration while the migration is underway. These operational changes are typically subject to Configuration Managementstandards imposed by an operations team.The Program Manager Role and Release Manager Role should work with operationspersonnel responsible <strong>for</strong> the existing technology to minimize and accommodate thesechanges. Long-lived migration projects may require a <strong>for</strong>mal process to connectoperational Configuration Management to project change control. Here are someadditional points to remember:● The major difference between a migration project and a new development projectis that the initial work has already been per<strong>for</strong>med to create the existing solution.The existing solution provides a working example of the goals which the solutionmust meet.● Depending on the long term objectives of the project, an existing change controltool and repository on the UNIX plat<strong>for</strong>m may be migrated to tools in the Windowsplat<strong>for</strong>m.● As migration involves making modifications to objects currently in production, carehas to be taken in how these objects are shared with the new development ef<strong>for</strong>t.As changes are discovered, there is the danger of modifying an object in theproduction thread. Creation of a separate project is recommended. In this situation,any changes made to the production thread should also be applied to thedevelopment (migration) thread. Appropriate controls have to put in place to handlethis.

36Envisioning PhaseConfiguration ManagementA major task in any database migration is the trans<strong>for</strong>mation of database objects, such assequences and code within the database, including stored procedures. Thesetrans<strong>for</strong>mations inherently change the source code. To maintain a known state as workprogresses towards migration, two aspects of Configuration Management have to beaddressed:● As discussed earlier, any change to the original environment after the baseline iscreated needs to be communicated to the project team and accounted <strong>for</strong>. Changemanagement in the area of configuration becomes critical if problems areencountered during the migration and you are <strong>for</strong>ced to return production to thepre-migration environment.● Any changes to the solution that occur during the Developing Phase andStabilizing Phase need to be documented and communicated to the entire projectteam.During the Stabilizing Phase, knowledge of and control over the test environmentconfiguration is critical to understanding the results that are received. If documentationexists identifying the aspects that have changed, the results of a given test can bevalidated against both current and future results.Some points to remember include:● Every configuration change should have a fallback or rollback path.● Configuration management tools, such as bug tracking software, should be able tooperate within the Windows environment.Assess RiskMSF stresses assessing project risk continuously throughout a project and makes thisthe responsibility of every team member. Risk is defined as the possibility of suffering aloss or, more specifically, the possibility of a negative outcome that can put the project inperil. The team comes up with an initial set of risks in the Envisioning Phase. This list isconstantly updated in later phases of the project as new risks begin to appear and oldones start to lose relevance. It is important to understand that in a migration projectissues are sometimes hidden, <strong>for</strong> example, in the design or implementation of a piece ofcode, which will appear only as the solution is being trans<strong>for</strong>med. Here are somequestions that you need to ask to understand the potential high level risks at the start ofthe project. These questions can help you generate the risk assessment list that canserve as the basis <strong>for</strong> your ongoing risk assessment and management <strong>for</strong> the project.● Are the project sponsors and stakeholders committed to support the project?● Does the migration team have the aggregate skill set to per<strong>for</strong>m the migration?● Are the project team members adequately motivated to per<strong>for</strong>m their role in theproject?● What will the impact on the business be if there is a delay in the projectcompletion?● Do you understand the real problems of the business and users that the project ismeant to address?● Have you accounted any possible temporary decrease in productivity due todistractions <strong>for</strong> the project staff from their daily duties to support the migrationproject or while the customers learn to use the new application?

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 37●●●●●●●●For the application suite to be migrated, do the vendors of any third-partyapplications provide technical support in the new environment?Is the application dependent on third-party software that is not compatible withWindows?Does the existing <strong>Oracle</strong> database contain technologies that SQL Server cannotdirectly implement?Have you fully considered the impact of the migration on other systems orapplications that currently rely on or interact with the existing solution?Does documentation exist <strong>for</strong> all the applications and databases, such asrequirements, models (logical, physical), and source code?How will you handle possibly unproductive situations from staff members (technicaland operational) who could be displaced by the migration?How will you handle possible scope creep in the migration project?Have you considered the impact of the migrated application failing to meet one ormore functional requirements?Manage RisksA good way to manage risks is to identify or anticipate potential risks be<strong>for</strong>ehand andcome up with a good mitigation and prevention strategy to deal with them in case theyoccur. The list of potential risks <strong>for</strong> a project is likely to be long, and not all potential riskscan be given the same amount of attention over the course of the project. It is there<strong>for</strong>eimperative to prioritize all the risks. This allows the team to focus more on the high priorityrisks, come up with suitable mitigation plans to prevent them from happening, and createcontingency plans to deal with them effectively if they materialize.This solution guide provides a risk assessment spreadsheet <strong>for</strong> you to monitor yourproject risks based on this methodology.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 393Planning PhaseIntroduction and GoalsIn the Planning Phase, the team defines the solution in detail — what to build, how tobuild it, who will build it, and when it will be built. During this phase, the initial vision andsolution concept defined in the Envisioning Phase is translated into practicalimplementation designs and plans <strong>for</strong> how to achieve it. Team members draw upon theirexpertise to create individual plans and designs in all areas of the project, ranging fromsecurity to budget to deployment. Likewise, individual team schedules and associateddependencies are identified. These plans and schedules are rolled into a master projectplan by the Program Management Role.The phase concludes when the project team agrees that the plans are sufficiently welldefinedto proceed with development, and the team, business sponsor, and keystakeholders approve the functional specification and the master project plan andschedule, usually at a milestone meeting. The <strong>for</strong>mal conclusion is marked by the secondmajor project milestone, Project Plans Approved.The key deliverables <strong>for</strong> the project team <strong>for</strong> the Planning Phase are:● Functional specification. The functional specification is the virtual repository ofproject and design related artifacts that are created in the Planning Phase. Theartifacts are primarily a result of design activities during the conceptual design,logical design, and physical design processes of the Planning Phase. The artifactscan include models such as case diagrams, usage scenarios, feature list, userinterface screen shots, database design, and so on.The key goals of the functional specification are to consolidate a commonunderstanding of the business, design, and user requirements; break down theproblem and modularize the solution logically; provide a framework to plan,schedule, and build the solution; and to serve as a contract between the team andthe customer and stakeholders.● Master project plan. The master project plan is a collection of individual plans thataddress tasks per<strong>for</strong>med by each of the six team roles to achieve the functionalitydefined in the functional specification. The master project plan documents thestrategies the team roles will use to complete their work. The solution concept thatthe team developed in the Envisioning Phase provides high-level approaches thatare developed into detailed plans in the Planning Phase. See Chapter 2,"Envisioning Phase," <strong>for</strong> the discussion of team roles.● Master project schedule. The individual team schedules apply a time frame to themaster plan. The master project schedule synchronizes project schedules across

40Planning Phase●the teams. Aggregating the individual schedules gives the team an overall view ofthe project schedule and is the first step toward determining a fixed ship date.Updated master risk assessment document. The master risk assessmentdocument that was developed during the Envisioning Phase is reviewed andupdated regularly during the Planning Phase.All of these deliverables are living documents, evolving as the project progresses.Though these documents can be modified, modifications must follow the changemanagement policies set up <strong>for</strong> the project during the Envisioning Phase.Table 3.1 lists the key activities that the team undertakes in the Planning Phase. Theresults of these activities are documented in this phase's deliverables.Table 3.1: Major Tasks, Deliverables, Owners, and Job AidsTasksDeliverablewhere resultsare documentedPrimary ownerJob Aidsprovided in thissolutionComplete detailedassessment of thecurrent environmentFunctionalspecificationProgramManagementAssessing theEnvironmentQuestionnaireDevelop thesolution design andarchitectureFunctionalspecificationProgramManagementValidate thetechnologyDevelop the projectplansFunctionalspecificationMaster project planDevelopmentTeam leads <strong>for</strong> allroles; plansconsolidated byProgram Manager* Development Plan* Test Plan* Deployment Plan* Pilot PlanCreate the projectschedulesSet up thedevelopment andtest environmentsReassess currentproject risksMaster projectscheduleRisk assessmentdocumentTeam leads <strong>for</strong> allrolesDevelopment andTestProgramManagementMigration RiskExposure RatingFormComplete a Detailed Assessment of the ExistingEnvironmentTo begin the migration process, an accurate and detailed assessment of the existingenvironment of your organization is essential. A high level assessment is carried out inthe Envisioning Phase. The detailed assessment in the Planning Phase is a follow upactivity.The in<strong>for</strong>mation collected by this assessment should be comprehensive enough to planthe specific details of the solution migration. For instance, a detailed assessment of theapplication will provide definitive in<strong>for</strong>mation on whether existing test plans can be reused

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 41to test the solution. Without this detailed in<strong>for</strong>mation about the existing environment,there is no way to accurately estimate the development, test, or deployment plans.The key elements of the environment that need to be assessed in detail include:●●●ApplicationDatabaseApplication infrastructureRefer to the Assessing the Environment Questionnaire job aid to help you assess themain areas of the environment.ApplicationA detailed assessment should be per<strong>for</strong>med <strong>for</strong> any application that is affected by themigration. A database application migration project assessment should not be limited toassessing the application alone; it should also include database connectivity.Assessment activities related to the database should include the following:● Note all database interfaces used by the applications and their types (OCI, ODBC,and so on).● Note the relationship between applications and databases. For example, note if adatabase supports multiple applications, or an application connects to multipledatabases.● Identify all the database, schemas, and schema objects that the applicationinteracts with.● Note the protocol that is used by the application to communicate with thedatabase. <strong>Oracle</strong> supports TCP/IP, TCP/IP with SSL, and named pipes.● Identify all encryption methods employed by the applications with the databases.● Identify the security features of the database used by the applications, such asauthentication, password features, single sign on, and so on.● Determine if there are any other network-related security authentication methodsused with the current application. Common <strong>Oracle</strong> authentication methods includeKerberos, Radius, DES Algorithm, RSA, and Cybersafe.● Note the data sources in use, such as ODBC, OLE DB, and ADO.In addition to questions related to database connectivity, here are some generalapplication assessment questions that you may need to ask.● Identify the programming language used <strong>for</strong> the main application as well as anysupplementary programs.● Identify the plat<strong>for</strong>m support (hardware and operating system), architecture, andcomponent interfaces of the existing application.● Locate any existing in<strong>for</strong>mation about the application. Is the source codeavailable? Other items that may help plan <strong>for</strong> migration include test scripts,documentation, process flow charts, and use cases.● Record any dependencies and characteristics, such as third-party libraries, UNIXutilities, or path names. Also, determine if the UNIX application uses X Windows,Motif, or xrt libraries.● Determine the security architecture of the application. This in<strong>for</strong>mation is importantbecause features and implementations are different between Microsoft Windows®and UNIX plat<strong>for</strong>ms.● Record any encryption protocols currently being used. SSL and PGP are twocommon encryption methods.

42Planning Phase●●Verify if the application uses daemon processes. This in<strong>for</strong>mation is requiredbecause UNIX applications can be started in the background and will continue torun even after a user logs off the system. Using application services in Windows2003 provides similar functionality.Check <strong>for</strong> any file system dependencies. This in<strong>for</strong>mation is required becauseUNIX and Windows use different file access methods.For more in<strong>for</strong>mation on assessing the application be<strong>for</strong>e migrating from UNIX toWindows, refer to the UNIX Application Migration <strong>Guide</strong>, available athttp://go.microsoft.com/fwlink/?LinkId=30832.DatabaseTo migrate an <strong>Oracle</strong> database to Microsoft SQL Server successfully, the project teammust assess the technical details of the current system.The following assessment activities should be per<strong>for</strong>med on the existing <strong>Oracle</strong>database:● Identify and record the database name and all configuration in<strong>for</strong>mation.● Determine the type of database being used. Common database types includeDecision Support System (DSS), Online Transaction Processing (OLTP), or acombination of the two.● Locate any existing design documents, such as data models, database creationscripts, or data definition language (DDL) specifications.● Record detailed in<strong>for</strong>mation on existing database structures, including tables,views, stored procedures, indexes, users, and roles.● Identify and record the current location of database files, such as Storage AreaNetwork (SAN), Network Attached Storage (NAS), or local attached storage.● Identify and record the disk space consumed by the existing database files. Also,obtain estimates of growth rate of the database files.● Evaluate the existing backup solution, including the frequency and type of backup(full, archive log, and so on).● Assess the database configuration in<strong>for</strong>mation, including the sort order andcharacter set.● Examine the frequency of data dumps and log dumps.● Determine the dependencies of the database on other databases or plat<strong>for</strong>ms.Common examples include distributed databases, replication, data marts, and datawarehouses.● Identify and analyze the server side scripts in use <strong>for</strong> activities such as data loads,batch processing, reporting, and administration.The Migration Analyzer tool, which is a part of the SQL Server Migration Assistant(SSMA), analyzes the source <strong>Oracle</strong> databases and produces vital statistics on the sizeand complexity of the migration. This tool can be downloaded fromhttp://www.microsoft.com/sql/migration. The beta version of this tool is available as of thedate of publishing this solution. Version 1.0 of the tool is slated to be available in June2005Application InfrastructureThe application infrastructure can be broadly classified as server-related and networkrelated.Server-related infrastructure relates directly to the hardware and software on theserver. Server-related items include operating systems, processors, memory, storage,

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 43tape drives, and file systems. Examples of network-related infrastructure include routers,firewalls, switches, domain name servers (DNS), and virtual private networks (VPN).Security infrastructure is classified under both server-related and network-relatedinfrastructure. Common items within the server security infrastructure are NetworkIn<strong>for</strong>mation Services (NIS and NIS+) and Lightweight Directory Access Protocol (LDAP).The following assessment activities should be per<strong>for</strong>med <strong>for</strong> server-related infrastructure:●●●●Check the capacity and per<strong>for</strong>mance of the servers and server clusters of theexisting environment. Also verify if the clusters are situated in single or multiplelocations.The hardware configuration details need to be gathered <strong>for</strong> any dependencies thatmight affect the migration, including architecture (32-bit versus 64-bit, hyperthreading,hybrid), processor speed, number of CPUs, and the number of availablesockets <strong>for</strong> upgrades.Record any pertinent in<strong>for</strong>mation about the RAM installed in the server, includingsize, configuration, and number of open slots available <strong>for</strong> upgrades.Verify disk storage needs <strong>for</strong> database files and the disk space consumed <strong>for</strong> theexisting database files. Identify the storage requirements, such as:● Amount of space needed <strong>for</strong> current and growth factors● Spindle RPM (disks: 15000 RPM versus 10000 RPM; SAN: 1 gbps versus 2gbps)● Throughput (theoretical I/O, current I/O, anticipated I/O) <strong>for</strong> each element ofthe storage system● Disk size(s)● RAID levels● Storage Architecture (SAN, NAS, external storage, internal storage)The following assessment activities should be per<strong>for</strong>med <strong>for</strong> network-relatedinfrastructure:● Identify the existing network protocols and network bandwidth.● Examine the routers, switches, and firewalls <strong>for</strong> the existing solution. Verify theconfiguration and location of firewalls and proxies.● Assess the network topology that exists in the organization.● In<strong>for</strong>mation about the network infrastructure needs to be identified, including thelogical organization of the network, name and address resolution methods, andnetwork naming conventions.● Analyze the network sites and the bandwidth between the sites. This in<strong>for</strong>mationcan be used to plan optimum strategies and schedules <strong>for</strong> installation anddeployment.● Assess the trust relationships and policy restrictions of the existing solution.Develop the <strong>Solution</strong> Design and ArchitectureThe Planning Phase of the MSF Process Model includes three design processes:conceptual, logical, and physical. These three processes are not per<strong>for</strong>med in parallel.Instead, their starting and ending points are staggered. These processes are dependenton each other. The logical design is dependent on the conceptual design, and thephysical design is dependent on the logical design. Table 3.2 compares the three designprocesses.

44Planning PhaseTable 3.2: Comparing Conceptual, Logical, and Physical DesignType of Design Perspective PurposeConceptual DesignLogical DesignPhysical DesignViews the problem from theperspective of the user andbusinessViews the solution from theperspective of thedesign/architecture teamViews the solution from theperspective of thedevelopersDefines the problem andsolution in terms of usagescenarios and refinedrequirementsDefines the solution as alogical set of co-operatingobjects and servicesDefines the solutioncomponents andtechnologiesIn a migration project it is quite likely that you already have detailed design documents <strong>for</strong>the existing system. These documents can provide an excellent starting point <strong>for</strong> yourdesign process. Enhancements can be made to account <strong>for</strong> the additional requirementsand functionality <strong>for</strong> the new system.Build the Conceptual DesignThe first design process in the Planning Phase is conceptual design. Once completed,the conceptual design is used in the creation of the logical and physical designprocesses.Conceptual design is the process of gathering, analyzing, and prioritizing business anduser perspectives of the problem and the solution, and then creating a high levelrepresentation of the solution in the <strong>for</strong>m of detailed requirements. The team gathers highlevel requirements during the Envisioning Phase and documents them in the <strong>for</strong>m of usecases and usage scenarios. While producing the conceptual design, the team refinesthese requirements.Develop Detailed RequirementsA conceptual design records the system requirements in terms of the followingrequirements:● Business requirements● User requirements● System requirements● Operational requirementsEach of these is described under the following headingsBusiness RequirementsBusiness requirements describe the organization's needs and expectations <strong>for</strong> thesolution. These requirements exist at the managerial decision-making level and providethe context in which the solution will operate.Some example business requirements include:● The database migration from UNIX to Windows should be completed in the giventime frame.● The existing business rules and policies should be maintained on the new system.● Ef<strong>for</strong>t required <strong>for</strong> migration should justify the cost incurred.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 45●The existing level of per<strong>for</strong>mance and functionality should be maintained after themigration, including disaster recovery, availability, and scalability.User RequirementsUser requirements define the nonfunctional aspect of the user's interaction with thesolution. They help you to determine the user interface and per<strong>for</strong>mance expectations ofthe solution in terms of its reliability, availability, and accessibility. In addition, the userrequirements help you identify the training that the users will need to effectively use thesolution.Some example user requirements include:●●●The user should be able to use the same or similar interface as the applicationrunning on the UNIX system to minimize user retraining.The time taken to retrieve in<strong>for</strong>mation from the system should not increase.There should be comprehensive user manuals <strong>for</strong> the new system. Trainingmanuals should also be considered <strong>for</strong> new users.System RequirementsSystem requirements specify the detailed transactions and their sequence in the system.The requirements help the project team define how the new solution will interact with theexisting systems. Some example system requirements include:●●●After the migration, the new system should continue to interoperate withapplications as it did on the UNIX plat<strong>for</strong>m.The system should not require a user credential other than the credentials passedfrom logging onto the corporate network (single sign on).The system should support internal and remote users.Operational RequirementsOperational requirements describe what the solution must deliver to maximize operabilityand improve service delivery with reduced downtime and risks. Some exampleoperational requirements include:●●●●●The system should allow administrators to per<strong>for</strong>m their tasks both on-site andremotely.The system should be able to recover from critical failure without major impact andwithin service levels.The system should include a process <strong>for</strong> managing the total throughput andresponse time within the stated service levels.The system should be able to handle varying levels of user load and transactions.In addition, the site should be designed so that it can be modified and upgradedwithout affecting availability and per<strong>for</strong>mance.Large clients should be separated with respect to database infrastructure tominimize the impact on maintenance and availability.Build the Logical DesignThe logical design is the second step in creating the solution design. After identifying thebusiness and user needs in the conceptual design, the logical design defines how thedifferent parts of the solution will coordinate and work together. The logical designdefines the parts of the system, provides a framework to hold all the parts of the systemtogether, and illustrates how the system interacts with the users and other systems.

46Planning PhaseWhile creating the logical design, the team takes into account all the business, user,operational and system requirements that state the need <strong>for</strong> security, auditing, logging,scalability, state management, error handling, licensing, globalization, applicationarchitecture, integration with other systems, and so on.There are several ways to represent the logical design of a system. A commonly usedvisual modeling language is Unified Modeling Language (UML). A detailed discussion ofUML is out of the scope of this solution. For more in<strong>for</strong>mation on UML, refer to TheUnified Modeling Language User <strong>Guide</strong> (Booch, Jacobson, and Rumbaugh 1999) andUse Case Driven Object Modeling with UML: A Practical Approach (Rosenberg and Scott1999).Figure 3.1 shows a sample logical design <strong>for</strong> a system using the Logical Object Model, asdefined by UML. The sample design represents the system in terms of:● Objects. These are people or things in the system. "Order" is an example of anobject in Figure 3.1.● Services. These are the behavior or functionality associated with any object. Forexample, "Track Status()" is a service provided by the "Order" object in Figure 3.1.● Attributes. These are characteristics or properties of the objects. For example,"Order ID" and "Ship Date" are attributes of the "Order" object in Figure 3.1● Relationships. These represent ways in which objects are linked with each other.For example, the object Order and the object Order line item are shown to have anassociative relationship in Figure 3.1 by a thick line. This shows that they arerelated and a change to one affects the other.The objects, services, attributes and relationships can be obtained from the detailedusage scenarios that were developed in the conceptual design phase.The logical design represents a logical view of the complete system. Individual teams,such as those <strong>for</strong> User Interface (UI) development, the database development, and theapplication development can take this representation and start to build the detaileddesigns <strong>for</strong> their domain when making the physical design.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 47Figure 3.1Creating a logical design <strong>for</strong> the applicationLogical Design ConsiderationsThe logical design <strong>for</strong> an <strong>Oracle</strong> database migration project must take into account thechanges that will occur as a result of migration from <strong>Oracle</strong> to SQL Server. The followingitems should be considered:● Are there any dependencies between client applications and databaseconnectivity?● Do UNIX scripts support the client applications?● How are communications between the application and database secured internallyand over the internet?● How is data distributed across multiple databases and multiple servers?

48Planning PhaseExamining the conceptual design of the client application will provide an understanding ofhow it operates and is structured. This in<strong>for</strong>mation is used to create the physical designof the solution. Two additional design studies that may assist in creating the physicaldesign are discussed in the following section.High Level User Interface and Database DesignUsing the objects, services, attributes, and relationships identified in the logical design ofthe system, the team might decide to create a high-level user interface and databasedesign.The list of objects and services gives the team an idea about the kind of functionalityexpected by the users. The team can use this in<strong>for</strong>mation to design user interfaceelements such as buttons, text fields, and menu items.Similarly, the object and attribute in<strong>for</strong>mation of the logical design can be used to developan initial database design equivalent to the <strong>Oracle</strong> database being migrated.Build the Physical DesignPhysical design is the process of describing the components, services, and technologiesof the solution from the perspective of the development team. The goal of the design is toprovide clarity and detail <strong>for</strong> each of the development teams to develop their components,be it the user interface, business logic, database, or infrastructure.The physical design should include:● Class definition of applications.● Database schema <strong>for</strong> the solution.● Baseline deployment model that provides:● The network topology, showing hardware locations and interconnections.● The data and component technology, which indicates the locations of thesolution components, services, and data storage in relation to the networktopology.●●Component specifications that include internal structure of components andcomponent interfaces.Programming models that identify implementation guidelines <strong>for</strong> threading, errorhandling, security, and code documentation.A detailed discussion of physical design is out of scope of this solution. For detailedguidance on designing the data layer, designing the presentation layer, and designing thesecurity specifications, refer to chapters 7 through 9 of Analyzing Requirements andDefining Microsoft .NET <strong>Solution</strong> Architectures (Microsoft Press 2003).The physical design diagram allows you to see how all the components connect together.For completeness, it may include infrastructure elements outside of the scope of theproject such as firewalls or network connections that are not directly related to thesolution. It will help prove the security of the system, and may show potential throughputbottlenecks, or highlight single points of failure.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 49Figure 3.2 shows a sample physical design diagram. Your design considerations willrequire you to modify this example.Figure 3.2Creating a physical design <strong>for</strong> the application and database.The following sections will help you plan <strong>for</strong> a migration by identifying the variouscomponents of the physical design and outlining the typical design considerations thatare part of a typical migration.

50Planning PhaseIncorporate Design ConsiderationsWhile migrating, you may want to utilize some of the advanced functions that areincorporated into SQL Server and Windows Server 2003. Some references may exist<strong>for</strong> Windows® 2000 but the in<strong>for</strong>mation also applies to Windows Server 2003. For morein<strong>for</strong>mation, refer to the following resources:● Designing <strong>for</strong> scalabilityhttp://msdn.microsoft.com/library/default.asp?url=/library/enus/architec/8_ar_sa2_8rnd.asp● Designing <strong>for</strong> availabilityhttp://www.microsoft.com/technet/prodtechnol/sql/2000/plan/ssmsam.mspx● Designing <strong>for</strong> reliabilityhttp://www.microsoft.com/mscorp/twc/reliability/default.mspx● Designing <strong>for</strong> per<strong>for</strong>mancehttp://www.microsoft.com/sql/evaluation/compare/benchmarks.asphttp://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/ansvcspg.mspx● Designing <strong>for</strong> interoperabilityhttp://www.microsoft.com/technet/prodtechnol/sql/2000/deploy/sqlorcle.mspxHardware Design ConsiderationsIn addition to the advanced features available in SQL Server, there are many softwaretools available to assist in ensuring that the correct hardware is acquired. Some of thesetools are listed here:● Microsoft Datasizer Tool. This spreadsheet helps estimate table sizes. For morein<strong>for</strong>mation, refer tohttp://www.microsoft.com/downloads/details.aspx?FamilyId=564C5704-D4F5-4EE8-9F3C-CB429499D075&displaylang=en.● Dell Powermatch sizing tools. These tools are available to assist in selecting Dellhardware <strong>for</strong> use with SQL Server. For more in<strong>for</strong>mation, refer tohttp://www1.us.dell.com/content/topics/global.aspx/alliances/en/sizing?c=us&cs=555&l=en&s=biz.● HP sizing tools. These tools are available to assist in selecting HP servers <strong>for</strong> usewith SQL Server. For more in<strong>for</strong>mation, refer tohttp://h71019.www7.hp.com/ActiveAnswers/cache/70729-0-0-0-121.aspx.● Unisys System Sizing Tools <strong>for</strong> SQL Server. These tools are available to assistin configuring Unisys servers <strong>for</strong> use with SQL Server. For more in<strong>for</strong>mation, refertohttp://unisys.com/products/es7000__servers/business__solutions/oltp__database__server/sql__server__resources.htm.Validate the TechnologyParallel to the design process, the team will often validate the technologies being used inthe solution. During technology validation, the team evaluates the products ortechnologies to ensure that they work according to specifications provided by their vendorand that they will meet the business needs <strong>for</strong> the specific solution scenario.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 51SQL Server Editions and FeaturesWhile <strong>Oracle</strong> is available in Personal, Standard, and Enterprise Editions,SQL Server 2000 is available in the following editions:● SQL Server 2000 Enterprise Edition (64-bit)● SQL Server 2000 Enterprise Edition● SQL Server 2000 Standard Edition● SQL Server 2000 Developer EditionAll editions of Windows® XP and Windows Server 2003 include support <strong>for</strong> SQL Server.Support exists <strong>for</strong> many earlier versions of Windows, as well.As with <strong>Oracle</strong>, each edition is distinguished primarily by the availability of certainfeatures, progressing from Personal Edition to Enterprise Edition. SQL Server also offersseveral different editions. Each edition provides functionality based on scale as shown inTable 3.3.Table 3.3: SQL Server 2000 Editions ComparedOSRequirementsand ScalabilityOperating SystemEnterprise (64-bit) Edition* Windows Server2003 EnterpriseEdition* Windows Server2003 DatacenterEditionScalability * Up to 64processors* Up to 512 GB ofmemory* Maximumdatabase size of1,048,516 TBEnterpriseEdition* Windows Server2003 StandardEdition* Windows Server2003 EnterpriseEdition* Windows Server2003 DatacenterEdition* Up to 32processors* Up to 64 GB ofmemory* Maximumdatabase size of1,048,516 TBStandard Edition* Windows Server2003 StandardEdition* Windows Server2003 EnterpriseEdition* Windows Server2003 DatacenterEdition* Up to 4processors* Up to 2 GB ofmemory* Maximumdatabase size of1,048,516 TBFor a detailed preview of all the SQL Server features and supporting tools, refer tohttp://www.microsoft.com/sql/evaluation/features/byfunction/default.asp.For in<strong>for</strong>mation on features by edition, refer tohttp://www.microsoft.com/sql/evaluation/features/choosing.asp.While migrating to SQL Server, the choice of edition of SQL Server that is required tosupport the demands on the database has to be validated. Refer to the followingresource <strong>for</strong> a whitepaper that can aid in choosing the appropriate edition of SQL Server:http://www.microsoft.com/sql/techinfo/planning/SQLReskChooseEd.asp.

52Planning PhaseWindows Server 2003Windows Server 2003 is available in the following editions:●●●●Windows Server 2003, Standard Edition. For departmental and standard corporateworkloads.Windows Server 2003, Enterprise Edition. For critical or heavy server workloads.Windows Server 2003, Datacenter Edition. For high levels of scalability andreliability.Windows Server 2003, Web Edition. For Web serving and hosting.The goals of the Windows Server System are to promote operational efficiencies throughsimplified deployment, management, and security; to ensure high levels of dependability,per<strong>for</strong>mance, and productivity <strong>for</strong> application development; and to seamlessly connectin<strong>for</strong>mation, people, and systems.For more in<strong>for</strong>mation on the different editions of Windows Server 2003, refer tohttp://www.microsoft.com/windowsserver2003/evaluation/features/compareeditions.mspx.Technical Proof of ConceptAfter validating the technologies, the team creates a prototype project using a smalldatabase that contains a representative sample of the data, tables, and other objectsfound in the production databases. This process will validate the approach <strong>for</strong> themigration and provide useful experience when using the various tools that have beenselected.This prototype can also be used as a basis <strong>for</strong> a proof of concept, and ultimately thedevelopment of the solution itself. This initial proof-of-concept model often produces bothanswers and additional questions <strong>for</strong> the team. This in<strong>for</strong>mation helps in the riskmanagement process and identifies changes needed to the overall design that must beincorporated into the specifications.Here are some candidates <strong>for</strong> the proof of concept that are typically part of this type ofmigration:● Per<strong>for</strong>mance of binary large objects (BLOB) in storing, accessing, and updatingbased on differences in their storage architecture between SQL Server and <strong>Oracle</strong>.● Migration of sequences. Sequences are not supported by SQL Server, but thefunctionality can be duplicated.● Replacing reverse key indexes in <strong>Oracle</strong> with regular indexes in SQL Server.● Converting <strong>Oracle</strong> packages to SQL Server stored procedures.● Recreating <strong>Oracle</strong>'s profiles (resource and password) functionality using Windowssecurity.● Developing Windows auditing functions to replace specific <strong>Oracle</strong> functionality(session, privilege, and object auditing).

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 53Develop the Project PlansThe solution design that was created in the Envisioning Phase is used as the baselinewhile creating the project plan. The project plan also needs to consider the key successcriteria identified in Chapter 2, "Envisioning Phase." The project plans include:● Development plan● Stabilization plan (includes test plan and pilot plan)● Deployment plan● Operations plan● Budget plan● Training planIn addition to the above plans, a training checklist needs to be created that will identifythe existing and required skills. This will help you to plan the training that needs to beprovided when you do the work described in Chapter 20, "Operations."The development plan, test plan, and deployment plan are covered in detail under thefollowing headings.Development PlanThe development plan describes different aspects of the development endeavor, such astools required, methodologies and practices to be followed, schedule of events, andresources. The primary tasks of the development plan include:● Defining team roles● Identifying team, hardware, and software resources● Providing training to the team membersRefer to the development plan template provided with this solution to assist in creatingyour development plan.In general, it is recommended that the elements described in the following sections beincluded in a development plan.Development ObjectivesThese define the primary drivers that were used to create the development approach andthe key objectives of that approach. The development objectives <strong>for</strong> a migration projectdiffer from that of a new development. Most commonly, the key objectives are to:● Migrate the application with the least amount of change.● Create a SQL Server database which is almost identical in design andimplementation to the source <strong>Oracle</strong> database.● Migrate the entire solution to a Windows and SQL Server environment with theleast amount of change.Migration ListThis provides a detailed listing of the applications and databases that need to bemigrated as part of the current project.

54Planning PhaseOverall Delivery StrategyThis describes the overall approach to delivering the solution. Examples of deliverystrategy include staged delivery, depth-first, breadth-first, and features-then-per<strong>for</strong>mance.In migrations, the solution already exists and the delivery strategy consists of deployingthe replacement solution.Tradeoff ApproachThis defines the approach <strong>for</strong> making design and implementation tradeoff decisions. Forexample, you might agree to trade features <strong>for</strong> schedule improvements, or to tradefeatures <strong>for</strong> per<strong>for</strong>mance.Key Design GoalsThese identify the key design goals and the priority of each goal. Examples of designgoals in a migration include interoperability between a UNIX application and theSQL Server database or rewriting the application using the .NET framework.Development and Build EnvironmentThis describes the development and build environment and how it will be managed.Include in<strong>for</strong>mation on items such as source code control tools, design tool requirements,operating systems, or other software installed. If a development environment <strong>for</strong> theexisting application does not exist, it will need to be created. This situation is commonwhen the development of the applications to be migrated was originally outsourced.Development ToolsThese tools are used to assist in the development and test environments. For a detaileddiscussion of tools, see the "Set Up the Development and Test Environment" sectionlater in this chapter.<strong>Guide</strong>lines and StandardsThese list and provide references to all standards and guidelines to be used <strong>for</strong> theproject. Standards and best practices could differ substantially from the current<strong>Oracle</strong>/UNIX environment. However, applying new standards will require a tremendousrewrite, which could greatly affect the migration timeline. It is recommended that suchstandards be applied only to the components that are being rewritten or modified.Versioning and Source ControlThis describes how versioning and source control will be managed. This section includesidentification of the specific tools that will be used and how developers are expected touse them. Most source control tools work with code irrespective of plat<strong>for</strong>m. Due to thechange in operating systems, new software may need to be acquired. For instance, ifCVS or any other source control software is currently used in the UNIX environment,consideration should be given to migrating these functions to a Windows-basedalternative, such as Visual Source Safe.Build ProcessThis describes the incremental and iterative approach <strong>for</strong> developing code and <strong>for</strong> buildsof hardware and software components. It also describes how the build process will beimplemented and how often it will be implemented.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 55ComponentsThis provides a high-level description of the set of solution components and how they willbe migrated. In a migration project, most of the solution components should already exist.Configuration and Development Management ToolsThis identifies all the development tools the team will use during the project. This includestools <strong>for</strong> all steps in the project: development, testing, documentation, support,operations, and deployment.Design PatternsThis identifies the design patterns or templates that the team will use <strong>for</strong> this project andtheir sources. The team can acquire design patterns from both external and internalsources or create new design patterns. This in<strong>for</strong>mation will only be necessary indevelopment plans that involve rewriting the application.Development Team TrainingThis identifies the training necessary to ensure that the development team willsuccessfully develop the solution. This is a critical necessity in migrations because it isnot common to already have personnel in place that can adequately support both <strong>Oracle</strong>and SQL Server environments.Development Team SupportThis identifies the various types of support the development team will require, thesources of that support, the amount of support of each type that the team will require, andthe estimated schedule <strong>for</strong> support. Support may not exist <strong>for</strong> the target Windowsenvironment, and may need to be developed.Stabilizing Phase PlansDuring the Stabilizing Phase, the testing team conducts tests on a solution whosefeatures are complete. Testing during this phase emphasizes usage and operation underrealistic environmental conditions. The team focuses on resolving and prioritizing bugsand preparing the solution <strong>for</strong> release.During the Planning Phase, the team typically creates the following plans that will beused during the Stabilizing Phase:● The test plan● The pilot planTest PlanThe test plan describes the strategy and approach used to plan, organize, and managethe project’s testing activities. It identifies testing objectives, methodologies and tools,expected results, responsibilities, and resource requirements. This document is theprimary plan <strong>for</strong> the testing team. A test plan ensures that the testing process will beconducted in a thorough and organized manner and will enable the team to determine thestability of the solution. A continuous understanding of the solution’s status buildsconfidence in team members and stakeholders as the solution is developed andstabilized.The Test Role in the MSF Team Model is responsible <strong>for</strong> creating the test plan. This teamis also responsible <strong>for</strong> setting the quality expectations and incorporating them into the

56Planning Phasetesting plan. This template is available in the Tools and Templates folder in the zip filedownload of this guidance at http://go.microsoft.com/fwlink/?LinkId=45289.The key sections of a test plan include:Forms of Testing to Be Per<strong>for</strong>medThese include:● Code component testingIn a migration, the scope of changes made to the existing application varies fromminor connection string changes to a complete application rewrite. The goal oftesting is to ensure that any component modified matches the original features andfunctionality. Instead of basing the test results on a series of requirements, theexisting application can be used as a basis <strong>for</strong> comparison.● Database testingThis includes:● Physical architecture of database. Have the data files, transaction logs, andother components that comprise the database been created correctly?● Logical architecture of the database. Have the tables, views, storedprocedures, triggers, and other database objects been created successfully?● Data. Have the contents of the tables been transferred correctly? Do tablescontain the correct number of rows? Is the data valid?● Functionality. Do the stored procedures, triggers, views, and other itemscomprising T-SQL code operate in the same manner as the original <strong>Oracle</strong>objects?● Per<strong>for</strong>mance. Do the response times and throughput meet requirements andmatch user expectations?●●●●●Infrastructure testingInfrastructure testing ncludes the development and production environments, aswell as hardware, software, monitoring software, network, backup strategies, anddisaster recovery plans.Security testingThere are two levels of security testing, network level and application level, thatshould be tested:● Network level. Test access and privileges● Application level. Ensure that the correct users and permission levels exist inthe application and database.Integration testingIf the solution is deployed in phases, then test the integration of each phase. Eachincarnation needs to be tested <strong>for</strong> acceptable integration with other components.User acceptance and usability testingThese tests can often be recreated from the original design solution. The migrationshould meet the same goals as the existing solution. Any new or modifiedfunctionality should also be tested.Stress, capacity, and per<strong>for</strong>mance testingThese tests are important because the migrated solution will reside in a newenvironment. The hardware, operating systems, and software will be very differentthan the existing solution. Complete testing should be per<strong>for</strong>med on the solution.Stress testing can also be used to check database coexistence issues that mayoccur when there is a heavy load on the system.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 57●Regression testingTo ensure that the solution functions correctly while bugs are being corrected, aset of test cases should be available that can be executed as a regression test.Each time the test is run, the results should be logged and compared with theexpected results. Testing per<strong>for</strong>med on the original solution can be reused in mostscenarios. Using the same data, test cases should per<strong>for</strong>m identically between theexisting solution and the new solution being tested.Test Approach and AssumptionsDescribe at a high level the approach, activities, and techniques to be followed in testingthe solution. If different approaches are required <strong>for</strong> the solution’s various components,you need to specify which components will be tested by which approach. This approachis relevant to migrations, as not all components will have the same amount of change ortrans<strong>for</strong>mation. The test approach should be tempered based on the amount of change.Major Test ResponsibilitiesIdentify the teams and individuals who will manage and implement the testing process.Features and Functionality to TestIdentify at a high level all features and functionality that will be tested. Per<strong>for</strong>m thefollowing tasks on the most common problem areas in an <strong>Oracle</strong> to SQL migrationproject:● Ensure that the SQL Server edition acquired meets application requirements. Formore in<strong>for</strong>mation, see the "Validate the Technology" section in this chapter.● Verify that the database architecture follows best practices and will meetper<strong>for</strong>mance goals.● Ensure functions that have moved from the database into the application (and viceversa) during the migration are properly documented and tested.● Check any table design changes due to restrictions on SQL Server row size.● Test triggers that have been converted from <strong>Oracle</strong> to SQL Server.Items to include when testing application migration include:● Code changes● Security requirements● User connectivity and remote access● Connection string changes● Functionality changes. Consider both application and database <strong>for</strong> specific items.Some database items will affect the application.Type of Required HardwareThe type of hardware <strong>for</strong> the test setup should closely resemble the architecture that isproposed <strong>for</strong> the production environment. The availability of hardware may depend on itstype, its cost, and any other environmental factors that need to be considered at thelocation of the test setup. In situations where data does not exist to make a decision onthe production data, the test environment has to be planned to capture such in<strong>for</strong>mation.In some situations, using virtual machine software (such as Microsoft Virtual Server2003) to recreate test environments and per<strong>for</strong>m software testing is cost-effective.

58Planning PhaseLocation of Test SetupDecide on the location of the test setup. If development, testing, and production are inphysically distant (possibly offshore) locations, then decisions have to be made on how toset up the environments <strong>for</strong> optimal per<strong>for</strong>mance <strong>for</strong> each group. For example, if the testand production locations are far apart, creating copies of a large production databaseacross a WAN can be an issue. Also, the test environment should be isolated and shouldnot interfere with any production activity.Resources RequiredProvide <strong>for</strong> the different equipment required <strong>for</strong> the setup, such as power points; racks orstands; storage media, such as disks; and a backup system. Software, services, andtools <strong>for</strong> the test environment have to be procured and set up as per the instructionsprovided by the test team.Expected Results of TestsDescribe the results that should be demonstrated by the tests. This in<strong>for</strong>mation includesexpectations of both the solution team and the testers. This section also defines whetherthe results must be exactly as anticipated or whether a range of results is acceptable.The expected results originate from the existing solution. The migrated solution shouldper<strong>for</strong>m the same or better than the original system.DeliverablesDescribe the materials that must be made available or created to aid in conducting thetests and <strong>for</strong> presenting test results. In many migration situations, existing test scripts canbe reused.Testing procedures and walk-throughDescribe the steps the testing team will per<strong>for</strong>m to ensure quality tests.Tracking and Reporting StatusDefine the in<strong>for</strong>mation that test team members will communicate during the testingprocess. This section defines the specific test status in<strong>for</strong>mation that will be created anddistributed. This in<strong>for</strong>mation normally includes status in<strong>for</strong>mation <strong>for</strong> each test case andthe probability of completing the test cycle on schedule.Bug Reporting Tools and MethodsDescribe the overall bug reporting strategy and methodology. This section also defineswhat will qualify as a bug in the code, product features, and documentation.SchedulesIdentify the major test cycles, tasks, milestones, and deliverables. This section alsodescribes who is responsible <strong>for</strong> each test cycle and its tasks. In addition, it identifies theexpected start and completion date <strong>for</strong> each test cycle and the tasks within that cycle.When planning <strong>for</strong> test cases, identify the sections of code that have changed duringmigration and identify the functionality provided.Create test cases based on these functionality changes. When changes are minimal,such as a Java application that only requires the database connection string to bemodified, the test case should ensure that the application is connecting properly to the

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 59SQL Server database. In most migrations, updates to connectivity and APIs represent amajority of the changes.In situations where the APIs have been changed, test cases should be created to test thiscomponent change. These cases should test database queries and updates per<strong>for</strong>medby the application to ensure that results are as expected. Gather various scenarios ofusability and user interaction and repeat <strong>for</strong> each component. Query results anddatabase updates can be checked against the same functionality in the existing solution.Refer to the test plan template to assist in creating your test plan. This template isavailable in the Tools and Templates folder in the zip file download of this guidance athttp://go.microsoft.com/fwlink/?LinkId=45289.Pilot PlanThe pilot plan describes how the team will move the candidate release version of thesolution to a staging area and test it. The goal of the pilot is to simulate the equipment,software, and components that the solution will use when it is active. This plan alsoidentifies how issues discovered during the pilot will be solved. The pilot plan includesdetails about how to evaluate the pilot; the results of the evaluation will facilitate adecision whether to move the solution to production.Project teams often conduct one or more pilots to prove the feasibility of solutionapproaches, to experiment with different solutions, and to obtain user feedback andacceptance of proposed solutions. Pilot solutions implement only those subsets orsegments of requirements of the functional specification that are necessary to validatethe solution.Note Some projects may not require conducting a pilot. For example, if there are fewchanges to an application, the consensus may be not to per<strong>for</strong>m a pilot program.However, even in situations where an application is ported, it is important to rememberthat the solution include the application and the new SQL Server database back end.Because the back end database, environment, and plat<strong>for</strong>m will change in the newsolution, a pilot is recommended <strong>for</strong> highly critical applications. Pilots are alsorecommended <strong>for</strong> applications where specific per<strong>for</strong>mance criteria, such as responsetimes or throughput, must be met. Pilot programs can also be useful in situations wherethere is a redesign in the migration and the components work differently on the newplat<strong>for</strong>m.In addition, piloting can provide operational and deployment personnel practicalexperience with new technologies and can benefit the actual deployment schedule andoperational transition schedules.The pilot plan provides the means to validate the business requirements and thetechnical specification prior to deploying the solution into production. Planning the detailsof the pilot ensures that the participating project teams identify their roles, responsibilities,and resource requirements specific to pilot development, testing, and deploymentactivities.Refer to the pilot plan template <strong>for</strong> assistance in creating your pilot plan. This template isavailable in the Tools and Templates folder in the zip file download of this guidance athttp://go.microsoft.com/fwlink/?LinkId=45289.

60Planning PhaseDeployment PlanDuring the Deploying Phase, the team deploys the solution technology and components,stabilizes the deployment, transitions the project to operations and support, and obtainsfinal customer approval of the project. Planning <strong>for</strong> deployment starts in the PlanningPhase by developing a detailed deployment plan. This plan should be developed by theRelease Management Role with assistance from the rest of the team. See thedeployment plan template in the Tools and Templates folder in the zip file download ofthis guidance at http://go.microsoft.com/fwlink/?LinkId=45289.Key elements of the deployment plan are described in the following sections.Deployment ScopeThis section describes the solution architecture and scale of deployment. Thedeployment team needs to consider deployment of the database, server, and the clientapplications. Each has its own challenges that require a different process and set oftools.● Seats. This describes the magnitude of the deployment in terms of sites, numberof workstations, countries and regions, and other relevant size factors.● Components. This lists and describes the components to be deployed and anycritical dependencies among them.● Architecture. This describes the solution’s architecture and how it might affectdeployment.Deployment ToolsThe database and server deployment will often be on one or a few machines. They canbe deployed manually. However, the clients may have to be deployed over hundreds ofcomputers across the corporate network. This may require the need <strong>for</strong> softwaredistribution and deployment tools. These tools are discussed in the "Deploying the ClientApplication" section in Chapter 19, "Deploying Phase."BackupsBacking up of the solution and the source control of scripts must be carried out. Theitems that need to be backed up <strong>for</strong> which you need to plan include a snapshot of thesource code of the existing solution and the migrated solution. Include the versionin<strong>for</strong>mation and build in<strong>for</strong>mation.This ensures that the environment can be recreated later, if required. It also aids duringproblems, especially when a fallback is implemented. In a phased migration, backups ofthe source should be per<strong>for</strong>med between phases, as well as any other critical junctures,as deemed necessary. If a partial rollback is needed, backups can save time.Deployment ScheduleThis identifies the critical dates and anticipated schedule <strong>for</strong> the Deploying Phase.Deployment ResourcesThis identifies the work<strong>for</strong>ce that will be needed to complete the deployment and thesources of the personnel.<strong>Solution</strong> SupportThis describes how the users will be supported during the deployment.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 61●●●●Help desk. This describes the support provided to users and applications by thehelp desk team, including support <strong>for</strong> direct user questions and application issues,and also in-depth support <strong>for</strong> new or difficult issues.Desktop. This describes any changes in current workstation application supportthat might be required during deployment.Servers. This describes any changes in current server support that might berequired during deployment.Telecommunications. This describes any changes in current telecommunicationsupport that might be required during deployment.Coordination of TrainingThis describes how end-user and support staff training is coordinated with thedeployment schedule.CommunicationThe necessary in<strong>for</strong>mation, such as the dates <strong>for</strong> deploying and completing the migrationmust be communicated to the customers and all those who may directly or indirectly beaffected by the migration. The deployment plan should be made available to the entireteam so that each person is well in<strong>for</strong>med of what actions they are responsible <strong>for</strong> andwhen it should occur. This is especially critical in large migrations that have to beundertaken over a grueling schedule, such as a weekend.Work SchedulesTo prevent the business operations from being affected by the deployment, workschedules should be set accordingly. The work schedules should consider training theoperations personnel and end users.Resource AvailabilityThe resources in the production environment should be prepared <strong>for</strong> the solutiondeployment. The infrastructure, servers, and workstations should be prepared <strong>for</strong> thedeployment. The necessary installation files should be ready to conduct a smooth andtimely deployment. Spare disk drives, cables, network cards, power points, stands, andbackup power supply should be made available in case of failure in hardware during thedeployment. In many instances, such precautions are not taken until a solution is alreadydeployed. Hence it is important to produce a plan to capture all these tasks.● Assembling the team. The rollout team should be assembled and the training toper<strong>for</strong>m the deployment should be provided. The rollout team members could befrom the project team, but the team should also include members from theoperations staff because they need to develop a thorough knowledge of thefunctioning of the solution. Alternate team members should also be selected toprepare <strong>for</strong> contingencies.● Training the team. The deployment team should be given the necessary trainingand privileges to overcome the difficulties that could arise during the rollout. Thedifferent installation manuals and documentation should be provided to the rolloutteam. A special help desk should be set up <strong>for</strong> the users and the rollout team torevert to while deploying the solution.● Documenting unplanned procedures. During the rollout, some procedures mayhave been implemented which were a part of the rollout plan. The deploymentteam may need these procedures to stabilize the deployment or correctun<strong>for</strong>eseen situations created due to the execution of unplanned procedures.

62Planning PhaseThese emergency procedures should be documented and include the cause andeffect of the procedure adopted.Because there are risks involved, the risk management plan has to be reviewedand updated. The risk management template is available in the Tools andTemplates folder in the zip file download of this guidance athttp://go.microsoft.com/fwlink/?LinkId=45289.Deployment StrategiesThe main strategies that need to be considered <strong>for</strong> deployment include:● Cutover strategy. The critical area in a migration project where the existingsystem is shut down and the new system is ready to be implemented in theproduction environment. The cutover strategy focuses on the tasks, activities, andtime required during the final days of the project. The cutover strategies availableare:● Straight cutover. This strategy enables migration of the database from oneenvironment to another without taking any intermediary steps. This option isused when downtime does not limit the migration, and the migrated databasedoes not contain critical in<strong>for</strong>mation.● Parallel cutover. Replication is a strategy that is used by organizations that donot have the adequate downtime required to build and migrate a database. Adatabase is created in the new environment and data is migrated on acontinual basis. A process is put in place to replicate the current databasechanges into the new database synchronously or asynchronously.● Serial cutover. This option enables the database to be migrated in phases.This approach is usually implemented when multiple databases need to bemigrated or data within the database is portioned based on business functions.The serial cutover strategy is difficult to implement when the database iscomplex and interdependent with other infrastructure elements.●●Phase-out strategies. In large, complex migrations, the solution is rolled out inphases. This enables the team to assess and reduce the business risks. Phasingout enables the deployment to take place in small and manageable parts. Thereare two types of phase-outs:● Vertical phase-out. In vertical phase-out, modules are rolled out one at atime. This implies that both the source solution and the target solutioninteroperate. The advantage is that the solution is rolled out in manageableparts. The disadvantage is that data bridge programs between the twosolutions have to be deployed at each phase-out.● Horizontal phase-out. The horizontal phase-out covers the rolling out of thesolution in phases over the different geographical areas. While implementing ahorizontal phase-out, the differences in the environment conditions of thebusiness and applications should be taken care of.Fallback strategies. A fallback is necessary if the migration encounters difficultiesor delays that impacts business. This could result due to the following reasons:● Unfeasible migration strategy● Undocumented requirements or procedures● Insufficient testing● Disasters● Un<strong>for</strong>eseen situations

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 63Each phase and each action in the rollout has to be associated with an impact todetermine if a fallback is required whenever that action cannot be successfullycompleted. Dependencies <strong>for</strong> every action should also be mapped to <strong>for</strong>esee theimpact on tasks further down the chain. Every precaution to ensure that thefallback is successfully completed has to be undertaken. For example, in case of afallback, the licenses of the existing solution need to be still valid, and theencryption certificates need to be valid.A fallback plan should enable the solution to be rolled back to a consistent andstable state. Workaround strategies or contingency plans should be tried be<strong>for</strong>edeciding to fallback on the original database. The fallback strategies to beimplemented depend on the cutover strategies that are selected. The fallbackstrategy should accommodate <strong>for</strong> any transactions that were executed since thestart of deployment. To select the optimal fallback strategy, a list of the possiblefailures needs to be documented. The different fallback strategies available are:● Fallback after straight cutover. In case of a fallback in straight cutover, theUNIX environment needs to be frozen at the time the cutover started. Thus, incase of a fallback, it is possible to restart the UNIX environment with minimalef<strong>for</strong>t. A fallback may require re-establishment of broken sessions between thecustomer computers and the database. To reduce downtime and rework,during the fallback, checkpoints have to be established be<strong>for</strong>e clients aremigrated. Also, a subset of clients should be cut over and tested be<strong>for</strong>e therest of the clients. In addition, adequate time should be provided <strong>for</strong> a fallbackwith minimal user disturbance.● Fallback after parallel cutover. The fallback process involves reversing thedirection of replication that was used in the cutover, that is, SQL Server to<strong>Oracle</strong> database. Consequently, the <strong>Oracle</strong> database is updated <strong>for</strong> the periodof the cutover. The client side is the main technical area to be addressedduring the fallback. <strong>Migrating</strong> the clients in smaller batches can ease the painof reverting to the original environment.● Fallback after serial cutover. The fallback is similar to that in a straightcutover, with the entire migration viewed as a collection of smaller cutovers.The serial or phased cutover enables you to fallback to a previous consistentstate without having to undo all changes. You are also able to solve problemsin small increments.For more in<strong>for</strong>mation and assistance in developing your deployment plan, refer to thedeployment plan template.Create the Project SchedulesBased on the functional specification and the project plan, the team creates a projectschedule that defines the release date of the solution. The team may choose to divide theschedule functionally. For example, different sub test teams will work on testing differentfeatures of the solution. Each subteam will create its own schedule.A release date is decided after integrating the master project schedule with the schedulesfrom each team lead. A release date enables the team members to prioritize functions,assess risk, and plan effectively.Estimating the Ef<strong>for</strong>tAccording to the various functional components, each task is allotted to a team that isdeveloping the component. Each team prepares plans based on their role and

64Planning Phasedeliverables. Finally, all the plans are reviewed and dependencies between the plans areoutlined. These various plans are then merged into a master project plan.Estimating the teams' ef<strong>for</strong>t can be accomplished as follows:● Each team leader prioritizes the functions, roles, and responsibilities <strong>for</strong> the entireteam.● The team members are required to estimate their per<strong>for</strong>mance <strong>for</strong> each taskassigned. The time given to per<strong>for</strong>m an individual task should vary from one halfday to one week. If the time duration estimated is short, then the overhead inmanaging the task may be too high. If the time estimated is too long, thenmanaging the scope of work becomes too difficult.● Per<strong>for</strong>m bottom-up estimating to create accurate schedules. This method enablesthe individual per<strong>for</strong>ming the task to estimate the time taken to complete it. Theestimate is usually based on the individual's experience of per<strong>for</strong>ming a similartask. In addition, individuals that estimate time plans <strong>for</strong> their work feel moreaccountable <strong>for</strong> their work schedules.● Implement risk-driven estimating, which enables the team members to per<strong>for</strong>m thedifficult and highest risk tasks first. It permits individuals to minimize risk andprovides excess time to mitigate risk.When scheduling a migration, there are many time-related elements to consider. Forinstance, the development and test environment need to be set up be<strong>for</strong>e starting theDeveloping Phase to maximize team productivity, mitigate risks, and avoid delays. It isalso recommended to migrate the database be<strong>for</strong>e migrating the application. This is dueto object-level differences between the <strong>Oracle</strong> and SQL Server databases that may needto be modified.Migration environments also impact the schedule. For instance, projects that involveporting the application, such as Java, can be accomplished relatively quickly. By contrast,migration environments that require rewriting the application, such as <strong>Oracle</strong> Forms andPro*C, will need a longer development schedule. Also, it is more challenging to migratedata in OLTP environments than in batch processing environments.Skills can also affect the scheduling. In an optimal migration, a database administrator onthe team is skilled in both SQL Server and <strong>Oracle</strong> environments. If current databaseadministrators are only familiar with the <strong>Oracle</strong> environment, extra time should be allowed<strong>for</strong> job training and skill acquisition. The same applies to application developers. Inaddition, pilot testing and migrating smaller applications be<strong>for</strong>e the main application maybe beneficial to the project by providing the entire project team with experience that mayprove helpful while migrating the main application.After you have defined a schedule, you can allocate resources to it. You should:● Update the project plan with detailed allocation of resources.● Check and configure availability of resources, identifying any possible overuse ofresources.● Establish a baseline and track progress on tasks and budget.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 65Set Up the Development and Test EnvironmentsThe final tasks <strong>for</strong> the Planning Phase are setting up the development and testenvironments. Completing these tasks allow <strong>for</strong> a smooth transition into the DevelopmentPhase.In many ways, the development and test environments are similar. Both are modeled onthe solution environment, and both are used to refine the solution. There are alsodifferences between the functions of these two environments.The development environment is used to develop the migration solution <strong>for</strong> the database,client application, and server applications. In addition, the environment may go throughchanges as the solution is developed.By contrast, the test environment is more strictly controlled to ensure that it emulates theproduction environment. The test environment is used to complete all necessary testing<strong>for</strong> the database and application. The test environment must be as similar as possible tothe production environment so that stress and scalability tests will have a measure ofaccuracy.Often in migration projects, the development environment is used <strong>for</strong> testing once theDeveloping Phase has ended. In most situations, the test environment requires a higherlevel of per<strong>for</strong>mance than the development environment, and additional hardware willneed to be added.If you are reusing equipment, it is best to reload all operating systems, applications, anddata. This ensures that testing results will not be skewed by a system setting or error leftfrom the development environment.The test environment also has different requirements than the development environment.For instance, testing tools should be installed <strong>for</strong> tasks such as recording per<strong>for</strong>mancefactors, or to increase the load during stress testing.The tools required <strong>for</strong> development and testing are:● Database modeling tools <strong>for</strong> reverse engineering existing databases andgenerating data definition statements <strong>for</strong> the new environment. The more popularmodeling tools are AllFusion ERwin from Computer Associates and ER/Studiofrom Embarcadero.● Software development tools such Visual Studio .NET or Visual Basic .NET, Perl,Python, PHP, and Java● Software management tools <strong>for</strong> source control and bug tracking — Visual SourceSafe and Concurrent Version Systems (CVS) are the popular ones <strong>for</strong> sourcecontrol. PVCS from Merant and ClearQuest from Rational can be used <strong>for</strong> bugtracking.● An application debugger (if one is not bundled with the application developmenttool). Most applications come with their own built-in debuggers.● Software <strong>for</strong> administering <strong>Oracle</strong> and SQL Server. Both <strong>Oracle</strong> and SQL Serveroffer Enterprise Manager, which contains a comprehensive set of tools <strong>for</strong> alladministrative tasks. There are several third-party tools available, such as Toadand SQL Navigator from Quest, PL/SQL Developer from Allround Automations,Unicenter SQL-Station from Computer Associates, and Rapid SQL fromEmbarcedero.● Database and data migration tools. Tools that are aimed specifically at <strong>Oracle</strong> toSQL Sever migration are available from Microsoft.● UNIX interoperability tools such as SFU, FreeTDS, and so on.

66Planning Phase●●●Scripting tools <strong>for</strong> writing scripts <strong>for</strong> testing. Perl is a popular scripting languagethat is portable across UNIX and Windows. Windows Script is available fromMicrosoft.Per<strong>for</strong>mance monitoring and analysis tools <strong>for</strong> the various components of thesolution. Perfmon is a versatile tool <strong>for</strong> monitoring the Windows system and it cancapture statistics <strong>for</strong> any application that runs on a Windows computer. Filemonand Netmon can be used specifically <strong>for</strong> the file system and internet traffic.Scheduling tool <strong>for</strong> automating tests and <strong>for</strong> capturing statistics. Windowsscheduler can be used <strong>for</strong> this purpose. Autosys from Computer Associates andControl-M from BMC are also popular.For additional in<strong>for</strong>mation on testing, refer to Chapter 18, "Stabilizing Phase."

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 674Developing: Databases —IntroductionIntroduction and GoalsFor a migration project, the Developing Phase is the time when the team builds thesolution components — code and infrastructure as well as documentation. Typically, thiswork consists of modifying existing code in a way that enables it to work within the newenvironment. When new code is written, some aspect of the original component usuallyremains unchanged — <strong>for</strong> example, exposed APIs, or specific component behaviors.Both the modification of existing code and development of new code in this context areconsidered to be migrating activities.Although the development and migration work is the focus of this phase and thisguidance, the entire team is active. For example, some team members are creatingdeliverables such as training materials, rollout and site preparation checklists, andupdated pilot and rollout plans while others are doing functional testing. Somedevelopment work may continue into the Stabilizing Phase in response to test results.This chapter serves as an introduction to the database development-oriented chapters.Chapters 5 through 8 describe and demonstrate how to implement a Microsoft®SQL Server database that resembles the source <strong>Oracle</strong> database as closely aspossible. These chapters also describe how to produce a solution that meets yourorganization's requirements <strong>for</strong> per<strong>for</strong>mance, functionality, availability, scalability, andrecoverability. The following list provides an overview of the content in each of thedatabase development-oriented chapters:● Chapter 4: Developing: Database — Introduction. This chapter prefaces thedifferent tasks in migrating the <strong>Oracle</strong> database to SQL Server 2000.● Chapter 5: Developing: Database — <strong>Migrating</strong> the Database Architecture.This chapter describes the steps in creating an instance of SQL Server which isequivalent in architecture to the original <strong>Oracle</strong> database.● Chapter 6: Developing: Database — <strong>Migrating</strong> Schemas. This chapter showshow to migrate a schema owner and its objects to a SQL Server database.● Chapter 7: Developing: Database — <strong>Migrating</strong> the Database Users. Thischapter contains detailed steps in creating users in the SQL Server databases andgranting them the same kind of privileges they had in the original <strong>Oracle</strong> database.

68Developing: Databases — Introduction●●Chapter 8: Developing: Database — <strong>Migrating</strong> the Data. This chapter exploresthe different options in migrating the application data from <strong>Oracle</strong> to SQL Server. Itprovides details in the usage of each of the options.Chapter 9: Developing: Database — Unit Testing the Migration. This chaptercontains the processes <strong>for</strong> testing the migrated database, its objects and data.The Developing Phase <strong>for</strong>mally ends with the Scope Complete Milestone. At this majormilestone, the team gains <strong>for</strong>mal approval from the sponsor or key stakeholders. Allsolution elements are built and the solution features and functionality are completeaccording to the functional specifications agreed upon during planning. Table 4.1describes the major tasks that need to take place while migrating the database.Table 4.1: Major Tasks and DeliverablesTasksMigrate the <strong>Oracle</strong> database architectureMigrate the schemasMigrate the usersMigrate the dataDeliverablesSQL Server instance that is equivalent instructure to the sourceSQL Server databases housing applicationschemasSQL Server users with similar privileges asthe sourceComplete database ready <strong>for</strong> use<strong>Migrating</strong> the DatabaseBecause they are both relational databases, <strong>Oracle</strong> and SQL Server have moresimilarities than differences in their features and functions. Both <strong>Oracle</strong> and SQL Serverprovide all the core functionality expected of a RDBMS, including concurrency, security,backup, recovery, scalability, availability, session management, transaction management,storage management, resource management, and so on. Both exhibit a moderate degreeof compliance to ANSI standards. Hence migrating from <strong>Oracle</strong> on UNIX to SQL Serveron Windows® poses less of a challenge than would normally be expected whenmigrating from one proprietary computing system to another. Because SQL Server and<strong>Oracle</strong> are relational databases, it is not necessary to redesign the database. It is notnecessary to rearchitect the application <strong>for</strong> per<strong>for</strong>mance or security because the twoDBMSs are very similar in their architecture. The majority of the work involved is inaccommodating the differences in the implementation of items such as indexes, datatypes, and SQL and DBMS features, such as partitioning.To simplify the migration of the database, the entire process can be organized into fourmajor tasks:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 69Figure 4.1Tasks in the migration of a databaseEach of the four major tasks includes a set of subtasks as follows:1. Migrate the database architecturea. Build the SQL Server instanceb. Configure the serverc. Migrate the storage architecture2. Migrate the schemasa. Migrate the schemab. Migrate the schema objects3. Migrate the usersa. Create user accountsb. Create roles and grant privileges4. Migrate the dataa. Plan the data migrationb. Execute the data migrationIn Chapters 5 through 8, examples are provided <strong>for</strong> each of the major tasks and subtasksat the end of the chapter. The discussion of testing the migrated database is in Chapter9, "Developing: Databases — Unit Testing the Migration." <strong>Oracle</strong> DBAs who are new toSQL Server should also read Appendix A, "SQL Server <strong>for</strong> <strong>Oracle</strong> Professionals," whichprovides a condensed guide <strong>for</strong> educating <strong>Oracle</strong> DBAs about the internal architecture ofSQL Server by leveraging existing knowledge of <strong>Oracle</strong>. The appendix also providesin<strong>for</strong>mation about how to per<strong>for</strong>m some of the common administrative functions inSQL Server.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 715Developing: Databases —<strong>Migrating</strong> the DatabaseArchitectureIntroduction and GoalsThe first task in the migration of the database is to create an instance of SQL Server thatwill provide the container (the RDBMS) <strong>for</strong> creating schemas and schema objects to caterto the needs of applications. Your main focus when creating the database should be onits architecture: the instance architecture involving server resources, such as processorpower and memory; and storage architecture, including file systems. Your objective <strong>for</strong>both of these areas is to derive per<strong>for</strong>mance that is equivalent to or better than theoriginal solution.The two most common implementations of databases are Online Transaction Processing(OLTP) systems and Decision Support Systems (DSS). OLTP systems are characterizedby large numbers of short transactions that frequently add or modify data. DSS systems,on the other hand, contain large volumes of mostly static data imported into them fromOLTP databases, file systems, and other such systems <strong>for</strong> the purposes of analysis andreporting. There are fewer transactions in DSS systems, but they run much longer. OLTPsystem per<strong>for</strong>mance is influenced by locking. DSS per<strong>for</strong>mance is typified by large reads,sorts, computation, and so on.The guidance provided in this solution is focused on OLTP systems. The types ofoperations per<strong>for</strong>med in OLTP and DSS systems impose different demands on thedatabase resources. While the architecture <strong>for</strong> OLTP and DSS systems differs, resourceconsiderations are similar. Though there are some objects that are specialized <strong>for</strong> DSSsystems, most objects are common to both systems. As a result, the guidance providedapplies to DSS systems, as well.Build the SQL Server InstanceThis section discusses the planning and preparation <strong>for</strong> installing the SQL ServerRDBMS software. A more detailed discussion can be found in SQL Server Books Onlineunder the “Installing SQL Server” topic.

72Developing: Databases — <strong>Migrating</strong> the Database ArchitecturePre-Installation PlanningYou should follow these design guidelines <strong>for</strong> the layout of a SQL Server softwareinstallation and database files:● Independent subdirectories. Files should be separated by categories andinstance to minimize effects and ease navigation. When named instances of SQLServer are created, the associated directories are created with instance names <strong>for</strong>identification purposes.● Consistent naming convention <strong>for</strong> files. Use the following file name extensions:.mdf <strong>for</strong> primary datafiles, .ndf <strong>for</strong> secondary datafiles, and .ldf <strong>for</strong> log files. Thedefault file naming convention is dbname_data.mdf <strong>for</strong> the datafile anddbname_log.ldf <strong>for</strong> the log file.● Integrity of home directories. Keep the SQL Server software separate from thedatafiles. This allows the software to be moved or deleted without affecting theapplication.● Separation of administrative in<strong>for</strong>mation <strong>for</strong> each database. Store system datain the master database separate from other data.● Separation of tablespace content. Every instance of SQL Server comes with thesystem databases master, model, msdb, and tempdb.● Tune I/O load across all disks. SQL Server has filegroups, each with multiplefiles that give the same advantages as tablespaces. In addition, storage allocatedto an object is distributed evenly across all datafiles belonging to the filegroup.InstallationThe following important installation options have to be determined prior to installing SQLServer:● Instance name. SQL Server has a provision <strong>for</strong> a default instance where theinstance takes the network name of the server. Multiple instances with assignednames can also be created. SQL Server naming conventions do not precludereuse of <strong>Oracle</strong> instance names.● Network libraries. SQL Server can communicate using several network protocols.TCP/IP and named pipes are the most common. To minimize resource utilization,only configure those protocols that are required.● Service accounts. Like any other service, both SQL Server and SQL ServerAgent (the SQL Server scheduling service) require a Microsoft Windows® account.You should run SQL Server under a domain account. It does not have to be a localadministrator or a domain account that has local administrative privileges.● Authentication mode. Options available in SQL Server are WindowsAuthentication or Mixed mode. Mixed mode allows login access to SQL Servereither by a valid Windows account or a valid SQL Server login. The authenticationmode can be changed any time in the future. Changing the authentication moderequires that the database be restarted to take effect.● Licensing mode. Indicate whether this SQL Server is licensed by processor or perseat (Client Access License) and the number <strong>for</strong> the given mode.● Location of files. With <strong>Oracle</strong>, even though the installer provides the option ofcreating a starter database, installing the software and creation of databases aretwo independent events. Installing the SQL Server software also creates a"database system" with databases such as master, model, msdb, northwind,pubs, and tempdb created by default. The destination location of SQL Server

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 73application files and the datafiles <strong>for</strong> the default databases can be specified atinstallation.Configure the ServerA SQL Server instance can be configured similar to an <strong>Oracle</strong> instance. The areas thatare covered here include memory, CPU, and listener.Architecturally, both <strong>Oracle</strong> and SQL Server can be divided into instance and database.The instance is made up of memory areas and database processes. In SQL Server, thedivision of memory pool into sub-caches (buffer cache, procedure cache, log cache,connection context, and system data structures) based on function closely resembles the<strong>Oracle</strong> SGA and its components. SQL Server has threads that per<strong>for</strong>m similar work to the<strong>Oracle</strong> <strong>for</strong>eground and background processes.In <strong>Oracle</strong>, the characteristics and behavior of the database and the instance aredetermined by a large set of parameters stored in the initialization file (init.ora) or serverparameter file (spfile). These parameters cover a diverse set of resources, such asmemory, processes, network, disk, I/O, connections, files, character set, and so on.The non-default values of the <strong>Oracle</strong> initialization parameters can be obtained from theparameter file if one is in use. If a server parameter file is in use, the parameter valuescan be obtained using one of the following options:● Convert the server parameter file (spfile) to an initialization parameter file byexecuting the following statement:CREATE pfile FROM spfile● Query the database by executing the following statement:SELECT name, valueFROM sys.v$spparameterWHERE isspecified = 'TRUE'SQL Server does not have an equivalent <strong>for</strong> every initialization parameter. Theconfiguration options in SQL Server can be specified using SQL Server EnterpriseManager or using the sp_configure system stored procedure. Syntax <strong>for</strong> use is shown inthe following statement.sp_configure [option, [value]]A discussion of every <strong>Oracle</strong> initialization parameter is beyond the scope of this guide.The configuration options available in SQL Server can be categorized into userconfigurableand advanced. The advanced options, which are similar to <strong>Oracle</strong>’s “hidden”parameters, are either self-configuring or should be manipulated only with the advice of acertified SQL Server technician.Examples of <strong>Oracle</strong> parameters that have an equivalent configurable parameter inSQL Server are provided in Table 5.1:Table 5.1: Examples of <strong>Oracle</strong> Initialization Parameters with Equivalent inSQL Server<strong>Oracle</strong>Processesfast_start_mttr_targetSessionsdml_locksSQL Servermax worker thread optionsrecovery intervalUser connectionsLocks

74Developing: Databases — <strong>Migrating</strong> the Database ArchitectureSometimes a configuration option can be set at one of several different places. Forexample, the SQL Server max degree of parallelism parameter can be set using the<strong>Oracle</strong> DEGREE clause at the object or query level.Certain options which are configurable in one database may have a fixed implementationin the other. For example, the <strong>Oracle</strong> LOG_CHECKPOINT_INTERVAL andLOG_CHECKPOINT_TIMEOUT parameters used to tune checkpoints do not haveequivalents in SQL Server. In SQL Server, checkpoints occur automatically based on thenumber of redo records in the log. Similarly, UNDO_MANAGEMENT,UNDO_TABLESPACE, and ROLLBACK_SEGMENTS that define the storage <strong>for</strong>transaction rollback or undo data are implemented in SQL Server as part of thetransaction logs of each database.Configure MemorySQL Server has far fewer configuration parameters than <strong>Oracle</strong>. In <strong>Oracle</strong>, there areseveral parameters that are used to control memory allocation to the instance and itssub-components. Some of these parameters are● SGA_MAX_SIZE● DB_CACHE_SIZE● SHARED_POOL_SIZE● LARGE_POOL_SIZE● JAVA_POOL_SIZE● LOG_BUFFER● SORT_AREA_SIZESQL Server offers the parameters min server memory and max server memory, whichcan be used to limit the amount of server memory that can be utilized by the databasesystem. SQL Server cooperates with the operating system to dynamically adjust theamount of memory used based on the demands on the server from other applications.However, this behavior puts the burden on the dimensioning of the system so it iscapable of running the database with known loads and peaks and avoiding competingworkloads which might jeopardize the system resources available to the database. Allmemory areas within the memory pool are dynamically adjusted by the SQL Server codeto optimize per<strong>for</strong>mance and do not need any administrator input. Hence you will findvery few memory-related configuration parameters in SQL Server.The amount of memory that can be utilized by SQL Server can be configured either usingEnterprise Manager or through T-SQL. The two options are provided in the followingprocedures:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 75 To configure the amount of memory available <strong>for</strong> SQL Server in EnterpriseManager, follow these steps:1. Expand the server group.2. Right-click Server (Server Name\Instance Name), and then click Properties.3. Select the Memory tab.4. Select Dynamically configure SQL Server memory to set the memory rangeunder which SQL Server should operate. Select Use a fixed memory size (MB) toallocate a fixed amount of memory. The actual values can be selected using thememory slider graphic.The code <strong>for</strong> setting a range of memory and a fixed amount of memory <strong>for</strong> SQL Server isprovided in the following procedure. To configure a range of memory <strong>for</strong> SQL Server using T-SQL, enter thefollowing commands:USE masterEXEC sp_configure 'show advanced option', 1RECONFIGUREGOsp_configure 'min server memory', 100 -- 100MBRECONFIGUREGOsp_configure 'max server memory', 4000 -- 4000 MBRECONFIGUREGO To configure a fixed amount of memory <strong>for</strong> SQL Server using T-SQL, enter thefollowing commands:USE mastersp_configure 'show advanced option', 1RECONFIGUREGOsp_configure 'min server memory', 400RECONFIGUREGOsp_configure 'max server memory', 400RECONFIGUREGONote A database restart is required to activate the new settings of all advanced options.If the amount of physical memory exceeds 3 GB, then the Address WindowingExtensions (AWE) Windows feature has to be enabled to handle allocation to SQL Serverusing the configuration parameter awe enabled. When this feature is enabled,SQL Server stops dynamic memory management at the server level and the max servermemory parameter has to be set. If the max server memory parameter is set, cache

76Developing: Databases — <strong>Migrating</strong> the Database Architecturemanagement is similar to SGA sizing in <strong>Oracle</strong> but without the complications of tuning theindividual cache components. To configure SQL Server to use more than 3 GB of memory using T-SQL,enter the following commands:USE mastersp_configure 'show advanced option', 1RECONFIGUREGOsp_configure 'awe enabled', 1RECONFIGUREGOsp_configure 'max server memory', 6000RECONFIGUREGOBecause the memory requirements of a SQL Server instance are not the same as anequivalent <strong>Oracle</strong> instance, the SQL Server memory size has to be tuned during amigration. The following Per<strong>for</strong>mance Monitor counters can be used to check the amountof memory SQL Server is using:● SQL Server: Buffer Manager: Total Pages● SQL Server: Memory Manager: Total Server Memory (KB)● Process: Working SetThe dbcc memorystatus command can be used to view in<strong>for</strong>mation about memoryallocation. For more in<strong>for</strong>mation about memory usage and this command, refer tohttp://support.microsoft.com/?id=271624.The LOCK_SGA initialization parameter can be implemented in SQL Server using setworking set size. The allocated memory stays in physical memory and improvesper<strong>for</strong>mance because swapping is avoided. However, care should be taken thatallocating a fixed amount of memory to SQL Server does not impact the needs of otherapplications running on the same server.Set the CPU AffinitySQL Server has the capability of defining CPU affinity where CPUs can be dedicated toan instance. This can be controlled using the affinity mask configuration setting orEnterprise Manager. The priority boost configuration setting can be used to prioritizethreads. SQL Server SP1 has added an IO_affinity_mask switch, which can used atinstance startup to reserve CPUs to handle disk I/O associated with the instance. Use ofthe IO_affinity_mask configuration setting is only recommended <strong>for</strong> machines with morethan 16 CPUs.For more in<strong>for</strong>mation on setting up the I/O affinity mask, refer tohttp://support.microsoft.com/?kbid=298402.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 77Configure the ListenerThe <strong>Oracle</strong> listener can operate on any available port. The well-known default selection is1521. A default installation of SQL Server uses port 1433. If not configured manually, anamed instance picks up an unused TCP port during startup. Unlike <strong>Oracle</strong>, where asingle listener is shared by all instances, each SQL Server instance listens on its ownport. The SQL Server server name, database name, and port in<strong>for</strong>mation are required byclient applications to configure the data source or the connection string (in non-DNSconnections).Migrate the Storage ArchitectureThis section discusses the physical and logical storage structures found in SQL Server.This discussion is useful in understanding how to configure storage in SQL Server in amanner similar to the original <strong>Oracle</strong> database.Database data is physically stored in files. However, allocation of this space to thedatabase objects is done in logical units such as blocks, extents, and segments. Figure5.1 provides a comparison of the storage architecture in <strong>Oracle</strong> and SQL Server.Figure 5.1Mapping <strong>Oracle</strong> storage structures to SQL ServerThe organization of storage and its allocation has great significance on per<strong>for</strong>mance andmaintenance of a database. Due to the similarities in the storage architecture, theprinciples on which the source <strong>Oracle</strong> database was organized can be carried over intothe SQL Server database with relative ease. The following sections discuss each level ofthe storage hierarchy shown in Figure 5.1.BlocksIn <strong>Oracle</strong>, the smallest unit of storage is the data block. All data in the database isretrieved and manipulated in terms of blocks. The SQL Server equivalent of the datablock is called the page. In <strong>Oracle</strong>, the DBA chooses the default page size at databasecreation to be any of 2K, 4K, 8K, 16K or 32K. In SQL Server, the page size is fixed at 8K.With <strong>Oracle</strong> 9i, in addition to the default page size, up to five non-standard (non-default)

78Developing: Databases — <strong>Migrating</strong> the Database Architecturepage sizes can also be used <strong>for</strong> the tablespaces (and, consequently, the logical storagestructures).The SQL Server page has similar composition as the <strong>Oracle</strong> data block. The data pageconsists of page header, data rows, and row offset array (row directory). The headerleaves 8060 bytes of usable space <strong>for</strong> data rows and row offset. In <strong>Oracle</strong>, a data rowthat is larger than the usable space is broken into several row pieces (row chaining) andstored in multiple blocks. SQL Server does not allow rows larger than 8060 bytes. Thisrestriction in SQL Server, however, does not apply to rows containing large data types,such as text, image, and so on, which are stored differently.Within a SQL Server block, space is managed in a manner similar to that by <strong>Oracle</strong>’sAutomatic Segment Space Management (ASSM) option, where used and free space istracked using bitmaps. This has implications with respect to migrating to SQL Server. In<strong>Oracle</strong>, the choice of block size is driven by the type of database — OLTP or DSS/DataWarehouse. The advantage of large block size is mainly in terms of I/O per<strong>for</strong>mancebecause there is less overall cost <strong>for</strong> setting up fewer I/Os. Better I/O per<strong>for</strong>mance canbe achieved with smaller block sizes by using other techniques, such as multi-block read(DB_FILE_MULTIBLOCK_READ_COUNT), parallel reads and read ahead, or prefetch.The maximum I/O size, however, is dependent on the operating system. SQL Server alsouses a technique called scatter I/O that enables multiple unrelated blocks to be read in asingle I/O request.An advantage of larger block size is reduced amount of row chaining. This is a factorwhen tables contain rows with lengths larger than can be accommodated in a block.Reading of multiple blocks may be necessitated in a SQL Server database as comparedto <strong>Oracle</strong> databases with larger block size, but the per<strong>for</strong>mance can be compensated <strong>for</strong>by better hardware and I/O techniques.Based on the environment, large block sizes can impact cache per<strong>for</strong>mance. With largeblock sizes, <strong>for</strong> a fixed amount of RAM, the number of blocks in physical memoryreduces. For example, if 1 MB of memory can hold 500 blocks of size 2 KB, it can holdonly 125 blocks of size 8 KB. So the cache per<strong>for</strong>mance is dependent on the density ofthe block (number of rows per block) and the access pattern (random or sequential).Smaller blocks reduce contention while the overhead becomes a larger portion of theblock.In the migration, the move from differing block sizes in <strong>Oracle</strong> to 8 KB blocks inSQL Server does not pose any challenge. When migrating from <strong>Oracle</strong> (where multipleblock sizes are in use), the rows will be rearranged into 8 KB blocks. However, solutionshave to be created to accommodate rows with length greater than 8060 bytes. Suchsolutions are examined later in this chapter.Extents and SegmentsData allocation to schema objects (such as tables and indexes) and system datastructures (temporary segment, rollback segment) in <strong>Oracle</strong> and SQL Server is in termsof logical extents. <strong>Oracle</strong> provides parameters <strong>for</strong> appropriate sizing of the extents.SQL Server, on the other hand, uses fixed size extents of 8 pages (64 KB). <strong>Oracle</strong>extents — irrespective of whether they belong to dictionary or locally-managedtablespaces — are migrated to fixed 64 KB extents.Extents allocated to <strong>Oracle</strong> objects are dedicated to the object and do not contain blocksfrom other objects. This is not the case in SQL Server. SQL Server has two types ofextents: uni<strong>for</strong>m and mixed. In a uni<strong>for</strong>m extent, all pages are allocated to a single object,while mixed extents can have pages belonging to multiple objects. When a table or indexis created in SQL Server, initially it is allocated two pages out of mixed extent. When the

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 79table or index grows to eight pages, all future allocations use uni<strong>for</strong>m extents. As a resultof fixed size extents, fragmentation within the tablespace (filegroup in SQL Server) iseliminated.Because an extent is a contiguous allocation of blocks, large extents aid in better I/O ratewhile reading huge amounts of data. After moving to SQL Server, physical I/O will haveto be configured and tuned, as was the case with the change in block sizes.In <strong>Oracle</strong>, all extents of an object are collectively called a segment. While the concept ofsegment existed in version 6.5, SQL Server does not have an equivalent <strong>for</strong> the segmentfrom version 7.0 and later. The segment has no bearing on migration or per<strong>for</strong>mance.Tablespaces and DatafilesDatafiles are used to store persistent data in the database. For ease of management, oneor more datafiles can be grouped into logical tablespaces. The SQL Server equivalent ofthe tablespace is the filegroup. While filegroups are similar in function, their organizationdiffers from that of tablespaces. <strong>Oracle</strong> tablespaces are at the instance level. SQL Serverfilegroups come under and are associated with the individual databases. Figure 5.2illustrates the tablespace to datafiles hierarchy:

80Developing: Databases — <strong>Migrating</strong> the Database ArchitectureFigure 5.2Schematic mapping of <strong>Oracle</strong> files and tablespaces to SQL Server

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 81Table 5.2 captures some of the relations between tablespaces in <strong>Oracle</strong> and databasesin SQL Server that are not obvious in Figure 5.2.Table 5.2: <strong>Oracle</strong> Tablespaces and SQL Server Functional Equivalents<strong>Oracle</strong>System tablespaceTemporary tablespaceUndo (Rollback) tablespaceOnline Redo log"App Data" tablespace"App Index" tablespaceN/AN/ASQL Servermaster databasetempdb databaseTransaction logTransaction log"App" database —"Data" filegroup"App" database —"Index" filegroupmodel databasemsdb databaseThe following list describes how <strong>Oracle</strong> functionality is implemented in SQL Server:●●●●●Each of the SQL Server databases has its own security structures, such as users,privileges (permissions), and roles.Each of the SQL Server databases has its own administrative roles that bestowprivileges on the database.In SQL Server, the system catalog — which is analogous to the <strong>Oracle</strong> datadictionary — is broken up between the individual databases and the masterdatabase.In SQL Server, each of the databases has its own transaction log files, whichcombine the functions of the <strong>Oracle</strong> online redo logs and rollback segments.The tempdb database provides temporary storage <strong>for</strong> the entire SQL Serverinstance, and the temporary tablespace in <strong>Oracle</strong> is common to the entire <strong>Oracle</strong>instance.Tablespaces and filegroups provide the ability to better distribute data across multiplefiles <strong>for</strong> the purposes of per<strong>for</strong>mance. The grouping also helps ease administration ofbackup and recovery, maintenance, availability, and so on.Each SQL Server database is created with a primary file belonging to the default primaryfilegroup. Optionally, secondary datafiles can be added to the primary filegroup, oradditional filegroups can be created. The location of the files belonging to a database isrecorded in the master database and the primary file <strong>for</strong> the database. Data added toobjects of a filegroup are proportionally filled across all files belonging to the filegroup.A common concern among users when creating SQL Server databases is the lack of themultiplexing feature available in <strong>Oracle</strong> <strong>for</strong> control files and redo logs. This is not aconcern because SQL Server recommends the use of striped and mirrored devices(RAID 0+1) <strong>for</strong> transaction logs to preserve the level of protection against hardwarefailure obtained by log multiplexing. SQL Server recommends using RAID 0+1 <strong>for</strong> alldatabase datafiles. If RAID 0+1 cannot be implemented, at a minimum RAID 5 should beused to provide tolerance <strong>for</strong> hard disk failure. Apart from file systems, SQL Server alsosupports the use of raw partitions.Storage Definition <strong>for</strong> Tables and IndexesIn <strong>Oracle</strong>, the storage definition is used to specify the characteristics of tables andindexes. The following list provides in<strong>for</strong>mation on how these characteristics migrate toSQL Server.

82Developing: Databases — <strong>Migrating</strong> the Database Architecture●●●Physical attributes. These include PCTUSED, PCTFREE, INITRANS, andMAXTRANS. Of these parameters, SQL Server only offers an equivalent <strong>for</strong>PCTFREE through the FILLFACTOR clause. FILLFACTOR is available <strong>for</strong> indexesonly. A PCTFREE of 10 would correspond to a FILLFACTOR of 90.Tablespace. This is used in a manner similar to tables. The SQL Server equivalentis the ON filegroup_name option. A default filegroup can be specified <strong>for</strong> eachdatabase, and the default filegroup functions similar to the default tablespace of an<strong>Oracle</strong> user. If a filegroup is not specified during index creation, the index iscreated in the default filegroup <strong>for</strong> the database.Storage attributes. These override the defaults specified at the tablespace level,such as INITIAL, NEXT, MINEXTENTS, MAXEXTENTS, PCTINCREASE, and soon. Due to the fixed (64 KB) extents, these attributes have no relevance inSQL Server.Migrate System Storage StructuresAs has already been presented in this chapter, an <strong>Oracle</strong> database has the followingsystem structures that have a similar role in a SQL Server database. The configuration ofthese structures in an <strong>Oracle</strong> database can be used to provide a starting point <strong>for</strong>configuration in SQL Server.● System tablespace. In <strong>Oracle</strong>, the system tablespace houses the data dictionaryand the system rollback segments. The master database in SQL Server has asimilar role. The transaction log — which also holds the rollback in<strong>for</strong>mation — is ina separate file. Also, the data dictionary in the master database does not growbecause user object in<strong>for</strong>mation is stored in the primary file of the containeddatabase under the decentralized data dictionary model of SQL Server. Themaster database also has some of the in<strong>for</strong>mation that is stored in the control fileof an <strong>Oracle</strong> database. Based on these facts, it is appropriate to use the defaultmaster database settings.● Rollback or undo. In <strong>Oracle</strong>, a separate tablespace exists <strong>for</strong> holding rollbacksegments (manual and auto modes) whose size and number is dependent uponthe number of user connections and the amount of changes being made to thedatabase. These factors should be considered in sizing the transaction log inSQL Server.● Redo. There are several factors to consider while choosing the size of atransaction log. The source <strong>Oracle</strong> database has more than one schema that willbe migrated into separate SQL Server databases. For the same transaction, theamount of redo and rollback in<strong>for</strong>mation generated in SQL Server and <strong>Oracle</strong> isdifferent. The frequency of backup or truncation of the transaction log alsoinfluences the size. Hence prototyping is the best way to size the SQL Servertransaction log.● Temporary. The size of tempdb can be initially set to a conservative size ascompared to its <strong>Oracle</strong> counterpart, the temporary tablespace. The auto-incrementfeature should be set to ensure that transactions do not fail due to lack of space.Setting very small increments will also affect per<strong>for</strong>mance due to constant spaceoperations. The temporary space needs are based on the application needs, whichmay change a little as applications are migrated to a SQL Server environment.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 836Developing: Databases —<strong>Migrating</strong> SchemasIntroduction and GoalsThe next task is to create additional databases to house the application schema objectsand the objects that are migrated.Apart from the architectural differences mentioned in Chapter 5, there are alsodifferences in data models between OLTP and DSS systems. OLTP systems have morecomplex relations, with constraints used to en<strong>for</strong>ce business rules. DSS systems havesimpler and far fewer relationships between tables. Despite the differences betweensystems and schema modeling techniques (such as normalized, star, and snowflake), theimplementation of the physical schema uses the same set of objects, such as tables,indexes, and views. As a result, migration of the schemas and data is the same <strong>for</strong> allthese types. As in Chapter 5, the examples used in this chapter focus on OLTP systems,but the guidance is applicable to DSS systems, as well.A Microsoft® SQL Server database has the characteristics of an <strong>Oracle</strong> schemabecause objects can be created inside the database. In <strong>Oracle</strong>, the schema and thestorage (tablespaces) have independent identities — objects of a schema can be createdin different tablespaces, and a single tablespace can accommodate objects from multipleschemas. In this context, SQL Server databases are similar to <strong>Oracle</strong> tablespaces — anowner can create objects in different databases, and a database can contain objects fromdifferent owners.In spite of this fact, the database provides a higher degree of separation of theapplication data and security than is provided by schemas. SQL Server has beendesigned <strong>for</strong> the isolation of administrative duties at the database level. The system(catalog and roles) has been divided, with centralized functions that have instance-wideauthority under the master database and database-specific functions under the individualdatabases.Creating a SQL Server database <strong>for</strong> each <strong>Oracle</strong> schema is the ideal choice <strong>for</strong> thelogical separation of objects based on the business function (application) that is providedby the <strong>Oracle</strong> schemas. Subsequently, the schema's objects can be created under thedatabase.Tools are available from Microsoft that can assist in this step of the database migration.The Microsoft SQL Server Migration Assistant (SSMA) provides the Schema and Data

84Developing: Databases — <strong>Migrating</strong> SchemasMigrator, which specializes in the migration of the <strong>Oracle</strong> schema to SQL Server. TheSSMA also provides the SQL Converter tool, which converts SQL code found in <strong>Oracle</strong>objects (such as stored procedures) to their T-SQL equivalents. The SSMA tool suite canbe downloaded from http://www.microsoft.com/sql/migration. The beta version of SSMAis available as of the date of publishing this solution. Version 1.0 of SSMA is slated to beavailable in June 2005.Most tools that are employed in the administration of <strong>Oracle</strong> databases are capable ofextracting object definitions. Toad and SQL Navigator from Quest, PL/SQL Developerfrom Allround Automations, Unicenter SQL-Station from Computer Associates, RapidSQL from Embarcedero, and <strong>Oracle</strong> Enterprise Manager from <strong>Oracle</strong> are examples ofsuch tools.Modeling tools such as AllFusion (Erwin) from Computer Associates and ER/Studio fromEmbarcadero can also be employed to reverse engineer the <strong>Oracle</strong> database.The goal of this chapter is to show how an <strong>Oracle</strong> schema and its objects should bemigrated to SQL Server. Scripts should be used <strong>for</strong> per<strong>for</strong>ming most of the tasks in thisstep, because scripts make the migration easier to execute compared to the use of GUItools.Scripting Migrated Schema ObjectsThe development process is built on the requirement that when the development iscomplete, the code will be in place <strong>for</strong> unit testing and implementation. These scripts willallow recreation of the objects in a reliable manner when creating the database in theStabilizing Phase and the Deploying Phase. There are some basic rules that should befollowed when scripting the database <strong>for</strong> promotion to a staging environment <strong>for</strong> unittesting:● Script everything● Provide support documentation● Protect the scriptsEach of these basic rules is discussed under the following headings.Script EverythingScript everything associated with the database implementation. The Generate SQL Scriptfeature of SQL Server Enterprise Manager can be used to script each database object inthe migrated database. After the scripts are created, conduct a validation process toverify that the number of objects scripted is the same as the number of objects that existin the development database. This process is very important because it helps to ensurethat the database being promoted to the staging environment is identical to the databasein the development environment.Provide Support DocumentationProvide support documentation <strong>for</strong> each script. Comment the code to describe what ishappening in the script and include any observations gathered when it was last executed,such as how long execution took and how many rows were affected.Protect the ScriptsProtecting the scripts is very important <strong>for</strong> the database implementation. Treat the scriptslike production objects at this point. To ensure that the appropriate scripts are used whenthe database is promoted between development, staging, and production environments,

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 85keep the scripts in a secured directory or under version control. Versioning is veryimportant because an <strong>Oracle</strong> to SQL Server migration is not a mere mapping of objectsfrom one database to another. The differences between <strong>Oracle</strong> and SQL Server willrequire that some of the SQL statements be rewritten <strong>for</strong> the new environment. Thesechanges in SQL will also prompt changes to the database objects and their design.These changes will be driven by the application development (migration) process and notfrom within the database migration process described here. Only the development anddeployment teams should have access to the scripts.Migrate the SchemaThis section discusses the necessary steps in migrating the schema owner and settingup the storage in preparation <strong>for</strong> migrating the schema objects and its data.The high-level steps <strong>for</strong> migrating the storage architecture of a schema are:1. Map the storage architecture.2. Create a database <strong>for</strong> the schema.3. Create filegroups <strong>for</strong> the tablespaces.4. Add datafiles to filegroups.Each of these four high-level steps is discussed in detail under the followingsubheadings.Map the Storage ArchitectureThe first step in migrating an <strong>Oracle</strong> schema is to understand the storage architectureand how these architectural components will map to their equivalents in SQL Server.In<strong>for</strong>mation on the various characteristics of the tablespaces and datafiles in which the<strong>Oracle</strong> schema is stored has to be gathered.There are several tools, both from <strong>Oracle</strong> as well as third parties, which are used inadministering <strong>Oracle</strong> databases. Any of these tools can be employed to gatherin<strong>for</strong>mation on the tablespaces and datafiles. In the example migration that is provided atthe end of this section, methods <strong>for</strong> capturing the requisite data purely using SQL areprovided.

86Developing: Databases — <strong>Migrating</strong> SchemasFigures 6.1 and 6.2 provide a view of how the storage objects will align in <strong>Oracle</strong> andSQL Server.Figure 6.1<strong>Oracle</strong> schema illustratedFigure 6.2SQL Server schema equivalent

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 87Start by compiling a list of tablespaces that contain objects belonging to the schema andgather the following related in<strong>for</strong>mation:● Tablespace name.● Status. The status of an <strong>Oracle</strong> tablespace may be either ONLINE, OFFLINE, orREAD ONLY. If a tablespace is OFFLINE, then a decision has to be made if it isrequired to be migrated. Data in an offline tablespace cannot be accessed and ithas to be brought online <strong>for</strong> migration.● Tablespace contents. Only tablespaces whose tablespace content attribute is setto PERMANENT have to be migrated.● Logging attribute. Tablespaces may be set to LOGGING or NOLOGGING, whichspecifies the default characteristic <strong>for</strong> bulk operations against the objects in thetablespace.Note In SQL Server, the attributes of status, tablespace contents, and logging are setat the database level and not the filegroup level. If an <strong>Oracle</strong> schema has tablespaceswith more than one value <strong>for</strong> these attributes, more than one database will have to becreated in SQL Server. For example, if a schema uses two tablespaces (one isONLINE and the other READ ONLY), then the two tablespaces have to be mapped totwo separate databases in SQL Server. The two databases can then be set to ONLINEand READ_ONLY, respectively, using the state options available in SQL Server.Gather the following in<strong>for</strong>mation <strong>for</strong> each of the datafiles in the tablespaces:● File name● File size● File autoextensibility● Maximum file size● File auto extension incrementFrom the in<strong>for</strong>mation gathered about tablespaces and their datafiles, produce a map <strong>for</strong>the databases, filegroups. and datafiles to be created in SQL Server as shown in Figure6.2.Create Databases <strong>for</strong> the SchemaTo migrate the schemas from <strong>Oracle</strong>, databases are created in SQL Server <strong>for</strong> theschemas. The databases will hold the schema objects and their data. This sectionprovides details on how to create databases in SQL Server.To an <strong>Oracle</strong> DBA, creating a database means creating an entire database system thatcontains control files, redo logs, data dictionary and temporary tablespace. InSQL Server, these tasks are accomplished as part of the installation process. Hencecreating a database in SQL Server implies adding a user database to the already existingsystem databases. Members of the fixed server roles sysadmin and dbcreator, or anyuser with such privileges, can create a database. By default, the creator of the databasebecomes the owner of the database.Databases can be created either through Enterprise Manager or by using the CREATEDATABASE T-SQL command. Only members of the sysadmin and dbcreator fixedserver roles or users who have been granted the CREATE DATABASE permission cancreate a new database.The following basic characteristics of the database have to be decided be<strong>for</strong>e creating adatabase:

88Developing: Databases — <strong>Migrating</strong> Schemas●●●●●●Database name. Naming is constrained by the same rules as identifiers. Ameaningful name can be used and need not be the same as the name of the<strong>Oracle</strong> schema being migrated.Database owner. By default, the user who created the database becomes thedatabase owner (dbo). The owner can be changed using sp_changedbowner. Tomimic the <strong>Oracle</strong> schema, a login with the same name as the schema can bemade the database owner. A more detailed account of the implications of databaseowner and database object owner is provided in the "Qualifiers and NameResolution" section later in this chapter.Filegroups. These are the equivalents of tablespaces. A default primary filegroupis created during the database creation.Primary file. Every database is created with a default primary file belonging to thedefault primary filegroup identifiable by the .mdf file name extension. The primaryfile contains startup in<strong>for</strong>mation <strong>for</strong> the database and is used to store user data justas any other datafile. Only the size and growth characteristics can be changed.Secondary files. Additional files can be created in a database and associated withthe primary file group or any additional filegroup. The recommended file nameextension <strong>for</strong> secondary files is .ndf.Transaction log. Hold rollback and redo in<strong>for</strong>mation required to recover thedatabase. Notice that, unlike <strong>Oracle</strong>, where rollback segments and redo logs arecentral to the instance, every database has at least one transaction log.Transaction logs are not part of any filegroup.There are two ways to create a new database using Enterprise Manager: using theDatabase Properties dialog and by using the Create Database Wizard. An example ofeach of these procedures is provided here. To create a database using the Database Properties dialog, follow thesesteps:1. Right-click Databases, and then left-click New Database, or right-click Server(Server Name\Instance Name), then right-click New, and then left-click Database.2. In the Database Properties window, enter the database name in the Generalpane, the datafile and filegroup configuration in the Data Files pane, and thetransaction log configuration in the Transaction Log pane. To create a new database using the Create Database Wizard, follow thesesteps:1. Expand a server group, and then expand the server in which to create a database.2. On the Tools menu, click Wizards.3. Expand Database.4. Double-click Create Database Wizard.5. Complete the steps in the wizard.SQL Server also offers the CREATE DATABASE statement <strong>for</strong> creating databases.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 89 To create a database using the T-SQL CREATE DATABASE statement, use thefollowing syntax:CREATE DATABASE database_name[ ON][ < filespec > [ ,...n ] ][ , < filegroup > [ ,...n ] ][ LOG ON { < filespec > [ ,...n ] } ][ COLLATE collation_name ][ FOR LOAD | FOR ATTACH ]< filespec > ::=[ PRIMARY ]( [ NAME = logical_file_name , ]FILENAME = 'os_file_name'[ , SIZE = size ][ , MAXSIZE = { max_size | UNLIMITED } ][ , FILEGROWTH = growth_increment ] ) [ ,...n ]< filegroup > ::=FILEGROUP filegroup_name < filespec > [ ,...n ]Configure the DatabasesSQL Server is very similar to <strong>Oracle</strong> in its architecture and can be similarly configured. Inthe discussion of system configuration options, several options that apply to the individualdatabases but are set at the instance level are discussed. These options apply uni<strong>for</strong>mlyto all databases in the instance. In contrast, the following five different sets of options areset at the database level and apply only to the targeted database.● Auto options● Cursor options● Recovery options● SQL options● State optionsThese options are set using the ALTER DATABASE statement. A subset of the availableoptions can be set using Enterprise Manager. For a description of each of these options,refer to http://msdn.microsoft.com/library/default.asp?url=/library/enus/createdb/cm_8_des_03_6ohf.asp.If the source <strong>Oracle</strong> database is in NOARCHIVELOG mode, then the Simple Recoverymodel is chosen <strong>for</strong> the database and the Full Recovery model is used if the <strong>Oracle</strong>database is in ARCHIVELOG mode. If the <strong>Oracle</strong> tablespace is in read-only mode, thenthe corresponding database created in SQL Server <strong>for</strong> that database has to be set toread-only mode. Similarly, if the <strong>Oracle</strong> tablespace is offline, the corresponding databasecan be taken offline after the migration is complete. If logging has been turned off <strong>for</strong> the<strong>Oracle</strong> tablespace, then set the recovery model <strong>for</strong> the database to BULK_LOGGED.An overview of the SQL Server recovery models is available athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/dnsqlmag2k/html/dbRecovery.asp.

90Developing: Databases — <strong>Migrating</strong> SchemasCreate Filegroups <strong>for</strong> the TablespacesFilegroups in SQL Server are similar to tablespaces in <strong>Oracle</strong>. They are used to logicallygroup storage. When a database is created in SQL Server, it has one filegroup bydefault. Based on the number of tablespaces that the schema uses, additional filegroupshave to be created in the newly created database.Every database is created with a default primary filegroup that cannot be renamed ordropped. As a result, one of the tablespaces will have to map to the primary filegroupduring migration. Additional secondary or user filegroups can be created with userspecifiednames.In <strong>Oracle</strong>, tablespaces are created as locally managed or dictionary managed. The typeof tablespace determines what storage parameters can be used. Creating filegroups issimilar to creating tablespaces under <strong>Oracle</strong> except that a filegroup is added to a specificSQL Server database. Filegroups added to a database are called secondary filegroups,and they can be added to any database. Datafiles are added separately from thedefinition of a filegroup.The following two options are available <strong>for</strong> creating a filegroup. To create a filegroup using Enterprise Manager, follow these steps:1. Expand Databases and right-click Properties of the database to which thefilegroup has to be added.2. In the Database Properties window, left-click the Filegroups pane.3. Type the filegroup name in the next available empty line that follows the filegrouplisting. To add a filegroup to a database using T-SQL, execute the followingstatement:ALTER DATABASE database_nameADD FILEGROUP filegroup_nameAdd Datafiles to FilegroupsStorage has to be allocated in the SQL Server database to meet the requirements of theschema being migrated. Datafiles are added to filegroups much as datafiles are added totablespaces in <strong>Oracle</strong>.Adding a datafile in SQL Server is similar to the process used in <strong>Oracle</strong>. Thecharacteristics that can be set are related to auto-growth and are similar in function to<strong>Oracle</strong>'s AUTOEXTEND feature. An additional characteristic that does not exist in <strong>Oracle</strong>is the logical file name.Datafiles can be added to the primary filegroup as well as any secondary filegroups eitherthrough Enterprise Manager or using T-SQL. To add a datafile by using Enterprise Manager, follow these steps:1. Expand Databases and right-click Properties of the database to which thefilegroup has to be added.2. In the Database Properties window, left-click the Data Files pane.3. Add file in<strong>for</strong>mation in the next available empty line in the file listing. In the filegroupcolumn, select the filegroup name from the drop-down list. Also set the growthcharacteristics <strong>for</strong> the file.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 91 To add a datafile to the primary filegroup or secondary filegroups using T-SQL, use the following syntax:ALTER DATABASE database{ ADD FILE < filespec > [ ,...n ] [ TO FILEGROUP filegroup_name ]where ::=( NAME = logical_file_name[ , FILENAME = 'os_file_name' ][ , SIZE = size ][ , MAXSIZE = { max_size | UNLIMITED } ][ , FILEGROWTH = growth_increment ] )The TO FILEGROUP clause is not required to add datafiles to the primary filegroup.Add Transaction LogsIn <strong>Oracle</strong>, in<strong>for</strong>mation on transactions and the changes they make is recorded in redologs. The redo logs are common to the entire instance. In SQL Server, transactionalchanges are logged in the transaction log <strong>for</strong> the database whose objects are involved inthe transaction. A database is created with a single default transaction log. The defaulttransaction log has to be sized or new ones added based on the update activity againstthe database.Transaction logs can be added using a process similar to that used <strong>for</strong> adding datafiles,as shown in the following procedure. To add a datafile by using Enterprise Manager, follow these steps:1. Expand Databases and right-click Properties of the database to which thetransaction log has to be added.2. In the Database Properties window, left-click the Transaction Log pane.3. Add the transaction log file in<strong>for</strong>mation in the next available empty line in the filelisting. Also set the growth characteristics. To add a transaction log to a database using T-SQL, use the following syntax:ALTER DATABASE database{ ADD LOG FILE < filespec > [ ,...n ]where ::=( NAME = logical_file_name[ , FILENAME = 'os_file_name' ][ , SIZE = size ][ , MAXSIZE = { max_size | UNLIMITED } ][ , FILEGROWTH = growth_increment ] )Sample Schema MigrationThis section describes an example schema migration using the four steps that have beendescribed earlier. The HR schema that is bundled with the <strong>Oracle</strong> installation software isused to illustrate the steps in migrating a schema. The storage characteristics of thetablespaces used by the HR schema have been modified to demonstrate some of the

92Developing: Databases — <strong>Migrating</strong> Schemassteps that would be common in migrations. This example is conducted using the featuresand tools offered by <strong>Oracle</strong> and SQL Server and no third-party tool is employed.1. Extract the schema storage requirements by following these substeps:a. Produce a listing of tablespaces in which the schema has objects by using thefollowing statement:SELECT DISTINCT tablespace_name "TABLESPACE NAME"FROM dba_segmentsWHERE owner = 'HR'The owner in the statement is the name of the schema to be migrated. Theoutput is as follows:TABLESPACE NAME____________________________________________________________EXAMPLEINDXb. Obtain the characteristics of each of the tablespaces using the followingstatement:SELECT tablespace_name, status, contents, loggingFROM dba_tablespacesWHERE tablespace_name IN (SELECT DISTINCT tablespace_nameFROM dba_segmentsWHERE owner = 'HR')The owner in the statement is the name of the schema to be migrated. Theoutput is as follows:TABLESPACE_NAME STATUS CONTENTS LOGGING_______________________________________________________EXAMPLE ONLINE PERMANENT LOGGINGINDX ONLINE PERMANENT LOGGINGc. Find the datafiles associated with the tablespaces using the followingstatement:SELECT tablespace_name "TS NAME",file_name "FILE NAME", bytes/1024/1024 "SIZE MB",autoextensible, maxbytes/1024/1024 "MAX SIZE MB",increment_by*8192/1024/1024 "INCR SIZE MB"FROM dba_data_filesWHERE tablespace_name IN (SELECT DISTINCT tablespace_nameFROM dba_segmentsWHERE owner = 'HR')The owner in the statement is the name of the schema to be migrated. Theoutput is as follows:TS NAME FILE NAME SIZE AUTO MAX SZ INCR________________________________________________________________________EXAMPLE /u02/oradata/oracle92/example01.dbf 1000 YES 1000 100EXAMPLE /u02/oradata/oracle92/example02.dbf 100 YES 1000 100INDX /u03/oradata/oracle92/indx01.dbf 1000 YES 1000 50INDX /u03/oradata/oracle92/indx02.dbf 50 YES 1000 50Note The output has been re<strong>for</strong>matted to fit the page.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 93Figures 6.1 and 6.2 provide schematics <strong>for</strong> the hierarchical organization ofstorage in <strong>Oracle</strong> and SQL Server. Terminologies such as schema, database,tablespace, filegroup, datafile and transaction log are used here. These figuresare modified in Figure 6.3 and Figure 6.4 to show instances <strong>for</strong> theterminologies based on the HR schema:Figure 6.3<strong>Oracle</strong> storage map <strong>for</strong> sample HR schemaFigure 6.4Equivalent SQL Server storage map <strong>for</strong> sample HR schemaNote Instead of putting the HR_DATA files under the required PRIMARYfilegroup, a separate HR_DATA filegroup can be created. This helps make thefilegroup and datafiles correlation easier.2. Create and configure a new database in the SQL Server instance to hold theschema objects.a. Create the database.

94Developing: Databases — <strong>Migrating</strong> SchemasCreate the database with storage attributes selected using the in<strong>for</strong>mationgathered in step 1. The location of the files is dependent on the file system ofthe target Windows® server on which SQL Server is installed.Create the database using the following commands:USE masterGOCREATE DATABASE HRDATAON PRIMARY( NAME='HRDATA_01',FILENAME='E:\mssql\Mssql$corp1\data\hr_data_01.mdf',SIZE=1000MB,FILEGROWTH=0)LOG ON( NAME='HRDATA_LOG_01',FILENAME='G: \mssql\Mssql$corp1\log\hr_log_01.ldf',SIZE=10MB,MAXSIZE=100MB,FILEGROWTH=10)GOAll filegroups and files (data and transaction log) can be added at the time ofcreation of the database. The following is the syntax <strong>for</strong> doing this:USE masterGOCREATE DATABASE HRDATAON PRIMARY( NAME='HRDATA_01',FILENAME='E:\ mssql\Mssql$corp1\data\hr_data_01.mdf',SIZE=1000MB,FILEGROWTH=0),( NAME='HRDATA_ 02',FILENAME='E:\mssql\Mssql$corp1\data\hr_data_02.ndf',SIZE=100MB,MAXSIZE=1000MB,FILEGROWTH=100MB),FILEGROUP HR_INDX( NAME='HRINDX_01',FILENAME='F:\mssql\ Mssql$corp1\data\hr_indx_01.ndf',SIZE=1000MB,FILEGROWTH=0) ,( NAME='HRINDX_02',LOG ONFILENAME='F:\mssql\Mssql$corp1\data\hr_indx_02.ndf',SIZE=100MB,MAXSIZE=1000MB,FILEGROWTH=50MB)( NAME='HRDATA_LOG_01',FILENAME='G:\mssql\Mssql$corp1\log\hr_log_01.ldf',SIZE=10MB,MAXSIZE=100MB,

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 95b.GOFILEGROWTH=10)If the database is in ARCHIVELOG mode, then set the database to SimpleRecovery model; if it is in NOARCHIVELOG mode, then set to Full Recoverymodel. If the tablespace corresponding to the database is in NOLOGGINGmode, set the database to Bulk-Logged Recovery model. For more in<strong>for</strong>mationon the recovery models available in SQL Server, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/adminsql/ad_bkprst_4l83.aspIf the tablespace is in read only or offline mode, set the database to therespective mode after migration of the schema and data is complete.In this example, only the required primary filegroup with a primary file and thetransaction log are created as part of the database creation, and additionalfilegroups and files are added in subsequent steps to enable demonstration offunctions such as adding filegroups and data files.Configure the database.The mode <strong>for</strong> the <strong>Oracle</strong> database can be found using the following query:SELECT log_modeFROM v$database3. Add secondary filegroups.The HR_INDX filegroup can be added using the following commands:Use masterGOALTER DATABASE HRDATAADD FILEGROUP HR_INDXGO4. Add secondary datafiles.The Filename, Current Size, Autoextensibility, Max Size, and Increment Sizevalues retrieved from the <strong>Oracle</strong> database are used in creating similar datafiles <strong>for</strong>the HRDATA database. The primary file has already been created to match thefirst file in the HR_DATA tablespace.Create additional datafiles <strong>for</strong> the filegroups using the following commands:ALTER DATABASE HRDATAADD FILE( NAME='HRDATA_02',FILENAME='E:\mssql\Mssql$corp1\data\hr_data_02.ndf',SIZE=100MB,MAXSIZE=1000MB,FILEGROWTH=100MB)GOALTER DATABASE HRDATAADD FILE( NAME='HRINDX_01',FILENAME='F:\mssql\Mssql$corp1\data\hr_indx_01.ndf',SIZE=1000MB,FILEGROWTH=0),( NAME='HRINDX_02',FILENAME='F:\mssql\Mssql$corp1\data\hr_indx_02.ndf',SIZE=100MB,

96Developing: Databases — <strong>Migrating</strong> SchemasMAXSIZE=1000MB,FILEGROWTH=50MB)TO FILEGROUP HR_INDXGOIn this example, the focus was restricted to migrating a single schema. When migratingan entire database consisting of multiple schemas, the storage decisions will have to bemade using the best practices in storage allocation that were followed in <strong>Oracle</strong>. Placetemporary files on separate devices, separate data and log files, separate data and indexfiles, distribute I/O load across all available decisions, and separate tables with highactivity onto separate devices.For descriptions of best practices <strong>for</strong> the storage component of SQL Server, refer to thesection titled "Optimizing the Storage Component" athttp://www.microsoft.com/resources/documentation/sql/2000/all/reskit/enus/part10/c3361.mspx.Multiple schemas commonly share tablespaces in <strong>Oracle</strong> databases. Conceptually,SQL Server databases can be viewed more like <strong>Oracle</strong> tablespaces, and objects frommultiple schemas can be created in the same database. From this perspective,SQL Server databases function similarly to <strong>Oracle</strong> tablespaces. Figure 6.5 shows therelation between schemas and tablespaces, where a schema's objects can be in multipletablespaces and a tablespace can have objects from multiple schemas.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 97Figure 6.5Sharing of tablespaces/databases by multiple schemas/owners

98Developing: Databases — <strong>Migrating</strong> SchemasMigrate the Schema ObjectsIn the "Migrate the Schema" section earlier in this chapter, the focus was limited to theschema and its storage structures. This focus culminated in creation of databases withappropriate filegroups and datafiles. The database merely <strong>for</strong>ms the shell in which theschema objects will be enclosed. In this section, the following high-level steps inmigrating the schema objects are taken. These steps cover tasks related to schemaobjects and security.1. Create the schema owner.2. Create the schema objects.These steps are discussed in detail under the following subheadings.Create the Schema OwnerA schema owner in <strong>Oracle</strong> is a user with privileges to create objects. This is true inSQL Server as well. A user will have to be created in SQL Server in the database inwhich the schemas objects will be created. The user is then given privileges in thedatabase to create objects and populate the data.Users of <strong>Oracle</strong> and SQL Server databases can be classified as administrative users,application users, and schema owners.● Administrative users are users with special roles, such as database administratorand security administrator.● Application users are users who manipulate data in the owning user's tables.● Schema owners are users who create and maintain objects related to anapplication.The basics <strong>for</strong> the creation of all the three types of users are the same and are discussedin detail here. This knowledge is useful in creating application users and administrativeusers in Chapter 7, "Developing: Databases — <strong>Migrating</strong> the Database Users."A discussion of user accounts <strong>for</strong> each of the categories of users is presented in the restof this section. This discussion covers the differences in the logins between <strong>Oracle</strong> andSQL Server and the associated authentication and password functionality.AccountsIn terms of logins, all three types of users are created equal and are differentiated only bythe privileges they are bestowed. However, keeping with the practice of isolation andautonomy of user databases, logins are implemented a little differently in SQL Server. Itis important to understand this difference be<strong>for</strong>e starting the migration of schemas andusers. SQL Server has two levels (not types) of logins. In addition to the instance login,SQL Server requires separate logins be created <strong>for</strong> each database that the user orschema needs to connect to.To avoid confusion while referring to these various logins and accounts, this guide usesthe following terminologies commonly employed <strong>for</strong> the various logins in <strong>Oracle</strong> andSQL Server.● <strong>Oracle</strong> — Instance Level — user or username● SQL Server — Instance Level — login (login ID)● SQL Server — Database Level — user

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 99Logins provide access to the instance of SQL Server, whereas the user account controlsprivileges to objects inside the database. Figure 6.6 illustrates these relationships.Figure 6.6Migration of schema owner security from <strong>Oracle</strong> to SQL ServerThe migration of a schema owner from <strong>Oracle</strong> to SQL Server requires a login be createdat the instance level and a user be created at the database level. The impact of thisarchitectural change is observed in how objects are qualified. In <strong>Oracle</strong>, a schema objectis identified in SQL statements using schema.object_name. While migrating toSQL Server the schema object has to be fully qualified as database.owner.object_name.Even though there is no difference between the login aspects of the different types ofusers, only the schema owners and their migration are discussed here. A discussion ofapplication users and administrative users is postponed to the next task of the databasemigration, migrating the user, which is discussed in Chapter 7, "Developing: Databases —<strong>Migrating</strong> the Database Users."Authentication<strong>Oracle</strong> offers several options <strong>for</strong> the authentication of users. The two popular methods inuse are authentication by the database and authentication by the operating system. InSQL Server, the database mode is called SQL Server Authentication Mode and theoperating system mode is called Windows Authentication Mode. The databaseauthentication modes in <strong>Oracle</strong> and SQL Server are closely compatible and use a username and password pair. The operating system authentication is quite different between<strong>Oracle</strong> and SQL Server. <strong>Oracle</strong>'s operating system mode can only authenticate userswith local accounts on UNIX servers. Windows authentication <strong>for</strong> SQL Server is actuallyper<strong>for</strong>med by the domain and not the local account on the Windows server.Password ManagementThe <strong>Oracle</strong> RDBMS also provides password management functions, such as accountlocking, password lifetime and expiration, password history, and password complexityverification. The SQL Server RDBMS does not provide these services, and Windowssecurity is used to provide these features.Hence the migration of <strong>Oracle</strong> user names to SQL Server logins and users is dependenton the type of authentication in use as well as the requirements of password

100 Developing: Databases — <strong>Migrating</strong> Schemasmanagement. Table 6.1 shows the migration options <strong>for</strong> <strong>Oracle</strong> logins based onauthentication mode and the requirements on password management functionality.Table 6.1: Login Migration Based on Authentication Requirements<strong>Oracle</strong> AuthenticationMode<strong>Oracle</strong> PasswordManagementDatabase None DatabaseDatabase Required WindowsOperating system N/A WindowsSQL ServerAuthentication ModeAs a practice, the schema owner login should not be used <strong>for</strong> connection by theapplication instance (three-tier) or the application users (two-tier and three-tier). Hence aSQL Server authenticated login would be appropriate. However, <strong>for</strong> clients who restrictauthentication to Windows mode only because of security concerns, a domain loginshould be created <strong>for</strong> the schema owner.Based on the security model — either Windows users or groups — review the guidelinesin th e "SQL Server 2000 SP3 Security Features and Best Practices" white paperavailable athttp://www.microsoft.com/sql/techinfo/administration/2 000/security/securityWP.asp toassist with implementation.The following SQL statement can be used to extract the characteristics of the schemaowner account in the <strong>Oracle</strong> database:SELECT du.username,DECODE(du.password,'EXTERNAL','EXTERNAL','DB')"AUTHENTICATION MODE",du.default_tablespace, du.temporary_tablespace,dp.resource_name, dp.limitFROM dba_users du, dba_profiles dpWHERE du.profile = dp.profileAND dp.resource_type = 'PASSWORD'SQL Server does not have a CREATE USER statement. There are two system storedprocedures to add logins <strong>for</strong> the two modes of authentication, and a separate storedprocedure to add users at the database level.It is possible to add a new login <strong>for</strong> SQL Server using Enterprise Manager and systemstored procedures. T o add a new login to a SQL Server instance using Enterprise Manager:1. Expand the SQL Server Group and expand the Server (Server Name\InstanceName).2. Expand Security, right-click Logins, and then click New Login.3. Provide the login name and authentication method in the General pane. Systemand database level privileges can be granted through fixed roles under the ServerRoles pane. Object-level privileges can be granted either directly or through userroles in the Database Access pane.If the user is to be authenticatedby the domain, the correct domain should bepicked using the drop-down menu under Windows Authentication in the Generalpane. If domain authentication is used, the name of the login is in the <strong>for</strong>m Domainname\Domain login name. The default database that the user will connect to whenconnecting to SQL Server can be set under the Defaults heading in the Generalpane. This is different from the default tablespace setting <strong>for</strong> a user in <strong>Oracle</strong>.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 101By checking the appropriate database, the new user can be granted privileges on specificdatabases in the SQL Server instance by checking the appropriate database in theDatabase Access pane. This action also creates user accounts of the same name in therespective databases. For a schema owner, the db_owner role has to be granted <strong>for</strong> theprivilege of creating objects in the target database. The db_owner role has completeadministrative authority over the database and can be considered to be similar to the<strong>Oracle</strong> dba role but restricted to a single SQL Server database. To give the SQL Serverdatabase object owner equivalent of the resource role in <strong>Oracle</strong>, which grants DDLprivileges, the database role db_ddladmin can be used. SQL Server also has theCREATE TABLE, CREATE TRIGGER, CREATE VIEW and CREATE PROCEDUREroles that can be used to further curtail the capabilities of the schema owner. To add a new Windows authenticated login to a SQL Server instance using T-SQL, use the following syntax:sp_grantlogin[ @loginame = ] 'login_name'where login_name is of the <strong>for</strong>m domain_name\domain_login_name To add a new database authenticated login to a SQL Server instance using T-SQL, use the following syntax:sp_addlogin [ @loginame = ] 'login_name'[ , [ @passwd = ] 'password' ][ , [ @defdb = ] 'database_name' ][ , [ @encryptopt = ] 'encryption_option' ]where database_name specifies the database the login connects to after logging in(default database). While passwords are encrypted in SQL Server by default, the optionexists to skip encryption to allow custom password encryption by the application using adifferent algorithm.A user account should be created separately <strong>for</strong> the login in the default database. To create a user account to a SQL Server database using T-SQL, use thefollowing syntax:sp_grantdbaccess [ @loginame = ] 'login_name'[, [ @name_in_db = ] 'user_name'The name chosen <strong>for</strong> the user account can be different from that <strong>for</strong> the login account.Some of the other characteristics associated with a user or schema owner in <strong>Oracle</strong> thatneed to be addressed are:● De fault tablespace. In SQL Server, a default filegroup can be set <strong>for</strong> eachda tabase which has the same function and effect as the <strong>Oracle</strong> default tablespaceusing the following syntax.ALTER DATABASE database_nameMODIFY FILEGROUP filegroup_name DEFAULT● Temporary tablespace. By default, all users of SQL Server use the tempdbdatabase.● Tablespa ce quota. Quotas cannot be set in SQL Server at the instance,database, or filegrouplevel.

102 Developing: Databases — <strong>Migrating</strong> SchemasCreate the Schema ObjectsThis section discusses the migration of the schema objects from <strong>Oracle</strong> to SQL Server.The following is a complete list of objects that are classified by <strong>Oracle</strong> as schema objects:●●●●●●●●●●●●●●●●TablesClustersObject TablesIndex-organized TablesConstraintsTriggersIndexesViewsObject ViewsFunctionsStored ProceduresPackagesSynonymsSequencesDatabase LinksObject TypesTable 6.2 provides a high-level view of how the <strong>Oracle</strong> schema objects map toSQL Server.Table 6.2: SQL Server Objects that Replace <strong>Oracle</strong> Schema Objects<strong>Oracle</strong>TableClusterObject TableIndex-organized TableConstraintsTriggersIndexViewObject ViewSynonymSequenceDatabase LinkObject TypesProcedureFunctionPackageSQL ServerTableTableClusterTable (with clustered index)ConstraintsTriggersIndexViewN/AViewIdentityLinked ServerN/AStored ProcedureFunctionStored Procedure

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 103Some of these objects fall under broader classifications, such as tables and views. Whilethe discussion of some of the objects is beyond the scope of this guide, the following arecovered in this chapter:● Tables● Comments● Constraints● Triggers● Views● Indexes● Stored Programs, including functions, stored procedures, and packages● Objects not found in SQL Server, including sequences, synonyms, and databaselinksThe data definition language (DDL) <strong>for</strong> defining objects is in accord with ANSI SQLstandards. Because both <strong>Oracle</strong> and SQL Server maintain compliance with SQL-92 andSQL-99 standards, the syntax <strong>for</strong> defining objects is very similar.Identifiers and Naming<strong>Oracle</strong> object and column names are generally not case-sensitive. However, noassumptions should be made because they can be <strong>for</strong>ced to be case sensitive bydelimiting them (enclosing them) in double quotation marks (“). For example, the nameTRANSACTION_DATE can be made case sensitive by using “Transaction_Date”. Also,quotes can be used to create irregular identifiers such as “Transaction Date” (with a blankspace). Similarly, object and column names in SQL Server are not case-sensitive bydefault, but this default behavior can be changed by modifying configuration settings.Nonstandard or delimited identifiers can be created just as in <strong>Oracle</strong> using eitherquotation marks (“) or brackets ([ ]). Read the "Using Identifiers" section in SQL ServerBooks Online <strong>for</strong> rules about the construction and use of regular and delimited identifiers.<strong>Oracle</strong> table and column names are stored in data dictionary tables as uppercase stringsunless <strong>for</strong>ced to be case sensitive using delimiters. In contrast, the default SQL Serverbehavior is to store them in the case used when they were created. Because scripts <strong>for</strong>use with <strong>Oracle</strong> are written with such expectations, it is recommended you useuppercase identifiers while creating the objects in SQL Server (without <strong>for</strong>cing case byusing delimiters).Qualifiers and Name ResolutionThe names of objects are influenced by uniqueness requirements. <strong>Oracle</strong> object nameshave to be unique <strong>for</strong> a schema. In SQL Server, the same owner can own objects of thesame name in two different databases, that is, the combination of owner.table_nameneeds to be unique only within a database. Hence objects are qualified in <strong>Oracle</strong> as[schema.]object_namewhereas in SQL Server the complete qualifier is[database.]owner.]object_nameRules have been established in both <strong>Oracle</strong> and SQL Server <strong>for</strong> resolving anobject_name that is not qualified.In <strong>Oracle</strong>, the resolution is governed by synonyms and the concept of namespaces.Tables, views, snapshots, sequences, synonyms, procedures, functions, and packagesare in a single namespace. Triggers, indexes, and clusters each have their own individual

104 Developing: Databases — <strong>Migrating</strong> Schemasnamespace. The following order is used to resolve an object that falls in the tablenamespace:1. Table namespace of current user's schema2. Private synonym in the current user's schema3. Public synonymThe order is different in SQL Server, and resolution occurs as:1. Current user's schema in the current d atabase (set with USE statement)2. Database owner dbo of the current databaseThese relationships h ave to be taken care of during the migration of the users andapplication s. Because a user can own obj ects of the same name in multiple databasesand different users can hav e objects of the same name in the same database, it isrecommended that both database name and owner name be used to qualify objects inSQL Server.C hanging object identifiers to meet SQL Server standards can affect the applicationsusing them. However, changing the names of certain objects, such as indexes andconstraints, could be transparent to the business applications. Given the rules <strong>for</strong> namingin <strong>Oracle</strong> and SQL Server, there is no need to change the names of any of the identifiers.Note It is recommended that all objects in the migrated SQL Server database bequalified by database and owner because the rules <strong>for</strong> resolving names couldotherwise lead to the wrong object.Working with Data Types<strong>Oracle</strong> and SQL Server offer two types of data types: native data types and user defineddata types. The data types that are provided by the DBMS are called native data types orsystem data types. There are four basic cl asses of data: character, numeric, datetime,and binary. In addition, both <strong>Oracle</strong> and SQL Server have a few data types that areunique to each syste m. Tables 6.3 through 6.5 provide a complete mapping of <strong>Oracle</strong>data types to SQL Server data types that you should use when migrating.Care has been taken to suggest the closest possible data type both in terms of type ofdata being considered as well as the scale or size of the data that has to beaccommodated. A bad ch oice in data type can lead to a lot of problems during datam igration. The choice has to be driven by the definition in the source table and not by thedata in the table. Even when data migration is successful, the application may fail sometime in the future because the table canno t handle data that it was originally designed <strong>for</strong>.SQL Server data types can com<strong>for</strong>tably provide a close equivalent of the <strong>Oracle</strong> datatypes, and over sizing is not recommende d because it drives up the row size and thestorage requirements and will affect per<strong>for</strong>mance.Character or Alphanumeric DataNote that <strong>Oracle</strong> and SQL Server differ in the parameter used to define Char (Nchar),and Varchar (NVarchar) columns. For example, when CHAR(n) is used to specify acolumn data type in <strong>Oracle</strong>, n represents the number of characters, while in SQL Server itrepresents number of bytes.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 105Table 6.3 provides the SQL Server data types to use when migrating <strong>Oracle</strong> characterdata.Table 6.3: SQL Server Equiv alent <strong>for</strong> <strong>Oracle</strong> Character-based Data Types<strong>Oracle</strong> DataTypeMax Size (Bytes)SQL Server DataTypeChar 2000 Char 8000NChar 2000 NChar 4000Varchar 4000 Varchar 8000NVarchar 4000 NVarchar4000Varchar2 4000 Varchar2 8000NVarchar2 4000 NVarchar 4000LONG 2 31 Text 2 31 –1CLOB 2 32 Text 2 31 –1NCLOB 2 32 NText 2 30 –1Numeric DataMax Size (Bytes)<strong>Oracle</strong> has only one numeric data type, NUMBER, that can store zero, positive, negative,fixed, and floating point numbers, with a precision (p) of 38 digits and a scale (s) rangingfrom -84 to 127. Synonyms, such as NUMERIC, DECIMAL, FLOAT, INTEGER, can beused. SQL Server, on the other hand, has eight distinct named numeric data types thatconstrain the range of values they can hold. SQL Server also has three other data typesthat are of the number category: BIT, MONEY, and SMALLMONEY. Table 6.4 comparesnumeric data types in <strong>Oracle</strong> and SQL Server.Table 6.4: Finding Closest SQL Server Equivalent to <strong>Oracle</strong> Numeric Data Types<strong>Oracle</strong>Number(19,0)Int or Number(10,0)SmallInt or Number(6,0)Number(3,0)Number(p,0)Float or DoublePrecision or Number(38)Real or Number(19) or Float(63)Number(19,4)Number(10,4)SQL ServerBigIntIntSmallIntTinyIntDecimal or Numeric(p,s)FloatReal or Float(24)MoneySmallMoneyBinary Data<strong>Oracle</strong>'s BLOB replaces the older RAW and LONG RAW data types. The IMAGE datatype in SQL Server is the closest equivalent <strong>for</strong> <strong>Oracle</strong>’s BLOB data type, and it cansupport data up to 2 GB in size. The BINARY data type is a fixed size column whileVARBINARY is its variable size counterpart. Table 6.5 provides SQL Server equivalents<strong>for</strong> <strong>Oracle</strong> binary data types.

106 Developing: Databases — <strong>Migrating</strong> SchemasTable 6.5: SQL Server Equivalent <strong>for</strong> <strong>Oracle</strong> Binary Data Types<strong>Oracle</strong> DataTypeMax SizeSQL Server DataTypeBLOB 4 GB Image 2 GBRaw 2000 bytes Image 2 GBLong Raw 2 GB Image 2 GBBFile 4 GB (file pointer) N/ARaw(n) 2000 bytes Binary(n) orVarBinary(n)Max Size8000 bytesFor more in<strong>for</strong>mation about designing <strong>for</strong> and implementing BLOBs in SQL Server, referto http://www.microsoft.com/resources/documentation/sql/2000/all/reskit/enus/part3/c1161.mspx.Date and TimeHistorically, <strong>Oracle</strong> has had one data type, Date, which stores both date and timein<strong>for</strong>mation. In <strong>Oracle</strong> 9i, three new date and time data types have been added toaddress these shortcomings. The Timestamp data type can store fractional seconds upto 9 digits of precision. Time zone aware data types, Timestamp With Time Zone andTimestamp with Local Time Zone, are also available and they can handle daylightsaving time.SQL Server has two data types: DateTime and SmallDateTime. DateTime canrepresent the date and time in the range January 1, 1753 to December 31, 9999 with aprecision of one-three hundredth of a second. SmallDateTime can represent dates in therange January 1, 1900, through June 6, 2079 with a precision limited to the minute. The<strong>Oracle</strong> Date and Timestamp data types should be migrated to the DateTime data type.T he other two time zone aware data types do not have an equivalent in SQL Server.User Defined TypesA simple implementation of user-defined data types is the capability to define data typesas simple variations of the primitive data types. For example, defining a data type ZIP asa native type Char, with a length of 5, prov ides a uni<strong>for</strong>m definition that avoids anyambiguity between designers and developers.For example, the user-defined data type ZIP can be created as follows:CREATE TYPE zip_type AS OBJECT (zip char(5))/In SQL Server, the user-defined ZIP data type is:EXEC sp_addtype zip_type, 'char(5)'User-defined data types can be recursively used to define other user-defined data types.However, SQL Server does not support object types and their collections.TablesThe definition of the table data structure is the same, both in concept and <strong>for</strong>m, in both<strong>Oracle</strong> and SQL Server. This can be attributed to compliance with ANSI SQL standards.When designing the table data structure, data integrity is as important as data access. Toserve these purposes, <strong>Oracle</strong> provides several options <strong>for</strong> how data can be organizedwithin the table. Table 6.6 summarizes them:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 107Table 6.6: <strong>Oracle</strong> and SQL Server Table Types Compared<strong>Oracle</strong>Heap-Organized TableClustered Table -Partitioned Table -Nested Table -Temporary TableExternal Table -Object Table -Index-Organized TableSQL ServerHeapTemporary TableClustered IndexThe most common implementation of the table object is, in its basic <strong>for</strong>m, the heap-is the focus of the remainder of this organized table, and this table object section.The CREATE TABLE syntax, which creates a simple heap organized table, has threemajor parts:● Table name● Body (enclosed in parenthesis) — column name, column properties (data type,defaults, inline column constraints), out-of-line column constraints, tableconstraints● Storage specificationTable 6.7 compares the structural composition of the CREATE TABLE syntax in <strong>Oracle</strong>and SQL Server.Table 6.7: High-level Comparison of Table Definition Syntax<strong>Oracle</strong>SQL ServerCREATE TABLECREATE TABLE[schema.]table_name[[database.]owner.]table_name(column namecolumn data type(column namecolumn data typedefault expressioncolumn constraint, …defaults expressioncolumn constraint, …out of line or table constraintout of line or table constraint) )[storage_specification][storage_specification]The steps <strong>for</strong> creating a table in SQL Server using both Enterprise Manager and T-SQLare provided in the following procedures. To create a new table using Enterprise Manager, follow these steps:1. Expand Server, then Databases, and then the target database.2. Right-click Tables and select New Table. A new window appears <strong>for</strong> addingcolumns and other objects, such as indexes and constraints related to the table.This window is called the Table Designer tool.3. Add new columns in the top grid (column definition grid) along with the column datatype and nullability constraint. Some of the column's properties, such as Default

108 Developing: Databases — <strong>Migrating</strong> SchemasValue, can be provided in the Columns pane at the bottom. The Identity propertyis discussed in greater detail under the "Sequences" heading.4. Click the Table and Index Properties button found on the Columns window, orright-click anywhere in the column definition grid and select Properties to bring upthe table Properties window, which can be used to specify table level properties,constraints, and indexes. To create a new table using T-SQL, use the following syntax:CREATE TABLE[ database_name.[ owner ] . | owner. ] table_name( { < column_definition >| column_name AS computed_column_expression| < table_constraint > } [ ,...n ])[ ON { filegroup | DEFAULT } ][ TEXTIMAGE_ON { filegroup | DEFAULT } ]where < column_definition > ::= column_name data_type[ COLLATE < collation_name > ][ [ DEFAULT constant_expression ]The following list covers each of the components of the CREATE TABLE syntax:● Table and column name. As is the case in the "Identifiers and Naming" sectionearlier in this chapter, <strong>Oracle</strong> table and column names do not need any changeswhen migrated to SQL Server.● Column data type. The column data type <strong>for</strong>ms part of the table definition and isan integral part of creating a table. For the sake of reducing the complexity in thediscussion of tables (because there are several components to be dealt with here),the discussion of data types has been covered in the section "Working with DataTypes" earlier in this chapter.● Default value. The rules <strong>for</strong> specifying default value are very similar in bothdatabases, and default values can be specified in most cases. One of thedifficulties that may be encountered while migrating to SQL Server is the lack of anequivalent <strong>Oracle</strong> system function used <strong>for</strong> defining the default values. InSQL Server, a default value cannot be specified <strong>for</strong> a column of type timestamp.While <strong>Oracle</strong> treats defaults as a property of the column, SQL Server definesdefaults as a constraint.● Constraints. A detailed discussion of constraints appears in the "Constraints"section later in this chapter.● Storage properties. A detailed discussion of the storage architecture appears inthe "Migrate the Storage Architecture" section in Chapter 5, Developing:Databases — <strong>Migrating</strong> the Database Architecture." The only storage property thatcan be specified during table creation is the filegroup name. If a filegroup is notspecified, then the table is created in the database's default filegroup.In the Tab le and Index Properties window, the Table Filegroup drop-down listcan be used pick a filegroup from which the table will be allocated storage. TheT ext Filegroup drop-down list can be used to specify the fi legroup to be used <strong>for</strong>large objects, such as text and imagecolumns.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 109Not e In <strong>Oracle</strong> and SQL Server, tables can be created based on the definition of othertables.In <strong>Oracle</strong>, this is accomplished using the following statementCREATE TABLE table_name AS SELECT …The same can be achieved in SQL Server using the following syntax:SELECT … INTO table_nameThe various table types found in <strong>Oracle</strong> can be migrated as described in the following list.Detailed knowledge of each table type is not necessary to accomplish the migration.● Clustered table. Sometimes simply called clusters, these do not have anequivalent in SQL Server. The tables in the cluster have to be created as regularheaps. If rows are frequently accessed using a range search, a clustered indexmay be created on such column(s). Only one clustered index can be created on atable.This migration of clustered tables in <strong>Oracle</strong> to heaps in SQL Server will betransparent to the application and users.● Partitioned table. SQL Server does not have the partitioned table option.However, SQL Server offers partitioned views that are built using the samestrategy that was used in <strong>Oracle</strong> (be<strong>for</strong>e <strong>Oracle</strong> 8i) when true horizontalpartitioning was not available. This involves creating separate tables <strong>for</strong> each ofthe partitions, with a check constraint on the partition key column(s) to en<strong>for</strong>ce arange of values. A partitioned view is then created as a union of all the constituenttables. Details on the implementation of partitioned views can be found under thetopic "Creating a Partitioned View" in SQL Server Books Online.This migration of partitioned tables in <strong>Oracle</strong> to heaps in SQL Server will betransparent to the application and users.● Nested table. SQL Server does not support nested tables. The implementationstrategy used in <strong>Oracle</strong> can be imitated in SQL Server <strong>for</strong> migrating them. Thenested table column can be separated out into its own table (denormalized withsimilar definition) with a unique identifier used to connect the rows from the parenttable to the child table.● Minor modification to retrieve the data from the child table will be required inthe code to accommodate this change.● Temporary table. SQL Server supports both local and global temporary tables.SQL Server's local temporary table is equivalent to <strong>Oracle</strong>'s global temporary table( with the ON COMMIT PRESERVE ROWS ) because it provides the same level ofisolation from other sessions.Table 6.8 shows the syntax <strong>for</strong> creating temporary tables in SQL Server.Table 6.8: SQL Statements <strong>for</strong> Creating Temporary Tables in <strong>Oracle</strong> andSQL Server<strong>Oracle</strong>CREATE GLOBAL TEMPORARY TABLEtable_name …ON COMMIT DELETE|PRESERVE ROWSSQL ServerCREATE TABLE# table_nameLocal temporary tables in SQL Server work identically to <strong>Oracle</strong> temporary tablesand do not warrant any changes in the code. But the code pieces that assume thatrows are deleted automatically when working with tables with ON COMMIT

110 Developing: Databases — <strong>Migrating</strong> Schemas●●●●DELETE ROWS has to be modified to include a DELETE statement incompensation.External table. SQL Server does not have the option to create tables whose dataresides in flat files. Hence such data will have to be imported into the database.Object table. SQL Server does not support objects. The strategy <strong>for</strong> migratingobject tables to SQL Server is to flatten (absorb) the object column into the tableitself. This will induce only a small change in the SQL code that accesses the data.Index-organized table. The SQL Server clustered indexes are very similar to theindex-organized table (IOT), where the index is merged into the table instead oftwo separate structures. Clustered indexes are implemented in a fashion similar toindex-organized tables and have very similar features.Index-organized tables are sorted on the primary key. To migrate an indexorganizedtable to SQL Server, the CLUSTERED keyword can be used inconjunction with the PRIMARY KEY constraint, as described in the syntax given inTable 6.9.In SQL Server, a clustered index can be created on any column(s) of a table, but ithas to be created using the CREATE INDEX clause. If a clustered index is createdwith non-unique columns, SQL Server en<strong>for</strong>ces uniqueness by adding anuniqueifier to the rows with duplicates.In most cases, the primary key would be the ideal column <strong>for</strong> a clustered index. Anidentity column can also be used <strong>for</strong> a clustered key. In SQL Server, it isrecommended that every table should have a clustered index.Note Clustered indexes should be created be<strong>for</strong>e creating any nonclusteredindexes. If clustered indexes are planned <strong>for</strong> a table, defer creation of nonclusteredindexes (as part of PRIMARY KEY or UNIQUE constraint definition) during thetable creation in this step.Table 6.9 shows the SQL Server options <strong>for</strong> creating the equivalent of an <strong>Oracle</strong>index-organized table.Table 6.9: SQL Statements <strong>for</strong> Creating Index-organized Tables in <strong>Oracle</strong> andSQL Server<strong>Oracle</strong>CREATE TABLE table_name(column_name datatype,…)ORGANIZATION INDEX[ storage_definition ]SQL ServerCREATE TABLE table_name(column_name datatype,[ CONSTRAINT constraint_name ]PRIMARY KEY CLUSTERED[ ON filegroup | DEFAULT ])orCREATE [UNIQUE] CLUSTERED INDEXindex_nameON table_name( column_name [, …] )[ ON filegroup | DEFAULT ]Migration of tables is complicated by the referential integrity (<strong>for</strong>eign key) constraintsbetween tables. There are two options <strong>for</strong> how to migrate tables. Option one is to create

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 111tables in a specific order based on the <strong>for</strong>eign key constraints (parent tables first). Optiontwo is to create tables in any order, leaving out the <strong>for</strong>eign key constraints, and addingthem after all the tables have been created.CommentsThis is a property of the table that is often not documented and, hence, easily overlookedduring a migration. SQL Server does not have a comment property associated with tablesand columns. However, SQL Server provides the capability to associate customproperties, called extended properties, with objects.Comments can be added to tables and columns using Enterprise Manager and systemstored procedures. To add a comment on tables and columns using Enterprise Manager, followthese steps:1. Expand Server, then Databases, and then the target database.2. Left-click Tables to display the list of tables.3. Right-click the target table and left-click Design Table. This brings up the TableDesigner.4. Comments <strong>for</strong> the individual columns can be added in the Description field of theColumns pane at the bottom of the Table Designer window.5. In the Table Designer window, click the Table and Index Properties button foundabove the grid.6. Left-click the Tables pane of the Properties window. Table comments can beadded in the Description field in the Tables pane.The sp_addextendedproperty system stored procedure can be used to add any userdefinedmetadata to any column in SQL Server. This (and any other properties that area dded to the column) can be retrieved with the fn_listextendedproperty function.Table 6.10 shows the syntax <strong>for</strong> adding comments at the table and column levels.Table 6.10: Comparison of Functionality<strong>for</strong> Adding Comments in <strong>Oracle</strong> andSQL Server<strong>Oracle</strong>COMMENT ON TABLE table_name IScommentCOMMENT ON COLUMNtable_name.column_name IS commentSQL Serversp_ addextendedproperty 'comment',comment,'user', schema_name, 'table',table_namesp_addextendedproperty 'comment',comment,'user', schema_name, 'table',table_name, 'column', column_nameConstraintsConstraints are data integrity rules that are defined on the columns of a table to en<strong>for</strong>cecertain business rules. As an example, the specification of data types in the definition ofthe column constitutes a constraint.

112 Developing: Databases — <strong>Migrating</strong> SchemasTable 6.11 compares the availability of various types of constraints in <strong>Oracle</strong> andSQL Server:Table 6.11: Constraints Available in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong>NOT NULLUNIQUEPRIMARY KEYFOREIGN KEYCHECKSQL ServerNOT NULLUNIQUEPRIMARY KEYFOREIGN KEYCHECKThe functionality provided by <strong>Oracle</strong> and SQL Server to define constraints on columns,including the syntactic use of inline (or column) constraints and out-of-line (or table)constraints, is almost identical. The syntax in Table 6.12 illustrates the similarity. Out-of-have to be used when more than one column is involved in the definitionline constraintsof a constraint. If a constraint name is not specified using the CONSTRAINT clause, adefault name is generated by the database. The default names given by <strong>Oracle</strong> are of the<strong>for</strong>m SYS_Cn where n is a unique number generated by <strong>Oracle</strong>. The names provided bySQL Server are more suggestive with respect to the type of constraint (<strong>for</strong> example, CK,PK, and FK) and the table and column(s) involved. The syntax <strong>for</strong> the two options <strong>for</strong>defining constraints in SQL Server is provided in Table 6.12.Table 6.12: T-SQL Statements <strong>for</strong> Defining Inline and Out-of-line Constraints inSQL ServerInline (Column) ConstraintCREATE TABLE table_name(column_name datatype[ CONSTRAINT constraint_name ] [ [NOT ] NULL | UNIQUE | PRIMARY KEY |CHECK (condition) | REFERENCESref_table (ref_column) ])Out-of-line (Table) ConstraintCREATE TABLE table_name(column_name datatype,[ CONSTRAINT constraint_name ] [UNIQUE (column_name [, ...]) |PRIMARY KEY (column_name [, ...]) |CHECK (condition) | FOREIGN KEY(column_name [, ...]) REFERENCESref_table (ref_column) ])NOT NULL ConstraintIn both <strong>Oracle</strong> and SQL Server, the NOT NULL constraint can be specified only as acolumn constraint. More often than not, a constraint name is not provided while creatingNOT NULL constraints.When a column has not been specifically defined as NOT NULL in <strong>Oracle</strong>, it defaults tobeing nullable. When NULL or NOT NULL is not specified explicitly <strong>for</strong> a columndefinition, SQL Server uses the default of NOT NULL. For ANSI compatibility, setting thedatabase option ANSI_NULL_DEFAULT to ON changes the database default to NULL. InSQL Server, database and session settings can override the nullability specified by thecolumn definition.Some DBAs like to use meaningful names <strong>for</strong> all constraints so that errors referring tocons traint violations can be easily recognized in error messages. When migrating from<strong>Oracle</strong>, NOT NULL constraints with user-definednames can be queried using thefollowing syntax:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 113CREATE TABLE NOT NULL CONSTRAINTS(constraint_name varchar2(30),owner varchar2(30)table_name varchar2(30),column_name varchar2(30),search_condition clob);INSERT INTO NOT NULL CONSTRAINTSSELECT dc.constraint_name, dc.owner, dc.table_name, dcc.column_name,to_lob(dc.search condition)FROM dba_constraints dc, dba_cons_columns dccWHERE dc.owner = dcc.ownerAND dc.constraint_name = dc c.constraint_nameAND dc.constraint_type = 'C'AND dc.owner = 'user_name';COMMIT;SELECT *FROM NOT_NULL_CONSTRAINTSWHERE dbms_lob.instr(search_condition, 'IS NOT NULL',1,1) > 0;NOT NULL constraints can be created on tables using Enterprise Manager and theCREATE TABLE T-SQL statement. To create a NOT NULL constraint using Enterprise Manager, follow thesesteps:1. In the Table Designer, the Allow Nulls column should be unchecked <strong>for</strong> en<strong>for</strong>cingthe NOT NULL constraint and checked to indicate a NULL constraint. To create a NOT NULL constraint Using T-SQL, use the following syntax:CREATE TABLE table_name(column_name datatype [ CONSTRAINT constraint_name ]{ NULL | NOT NULL },…)Check ConstraintBoth <strong>Oracle</strong> and SQL Server use the same syntax to define check constraints; both alsohave similar restrictions in its usage. CHECK constraints can be defined on a singlecolumn or multiple columns at the table level. The conditions specified in the CHECKclause should evaluate to a Boolean value of TRUE or FALSE. The conditions can referto other columns but are restricted to the row being modified.Both <strong>Oracle</strong> and SQL Server allow multiple CHECK constraints on a column. A columnconstraint can only reference the column it is being created on. Each constraint can havemultiple concatenated conditions. The process to create check constraints on tablesusing Enterprise Manager and T-SQL is provided in the following procedures. To create a check constraint using the Table Designer in Enterprise Manager,follow these steps:1. In the Table Designer, click the Manage Constraints button to bring up the tableProperties window with the Check Constraints pane active.2. Click the New button to add a constraint.

114 Developing: Databases — <strong>Migrating</strong> Schemas3. A name of the type CK_table_name is inserted by the system in the Constraintname box. The constraint name can be changed to match the name given in<strong>Oracle</strong> only after entering a valid condition in the Constraint expression box. To create a check constraint using T-SQL, use the following syntax:Table 6.13 provides the syntax <strong>for</strong> the two alternative <strong>for</strong>mats available in SQL to specifyCHECK constraints during table creation. The syntax is the same in <strong>Oracle</strong> andSQL Server.Table 6.13: T-SQL Statements <strong>for</strong> Defining Inline and Out-of-line CHECKConstraints in SQL ServerInline (Column) ConstraintCREATE TABLE table_name(column_name datatype[ CONSTRAINT constraint_name ] CHECK(condition)…)Out-of-line (Table) ConstraintCREATE TABLE table_name(column_name datatype,…[ CONSTRAINT constraint_name ] CHECK(condition))Unique Constraints<strong>Oracle</strong> and SQL Server use indexes to en<strong>for</strong>ce unique constraints. In <strong>Oracle</strong>, if a uniqueor non-unique index already exists on the constraint columns, the index is used toen<strong>for</strong>ce the constraint without creating new ones. There<strong>for</strong>e, if a user-defined index ispreferred instead of a system-defined (and named) one, it is recommended that the indexbe created first. Unless a clustered index is explicitly specified, SQL Server creates anonclustered index on the unique key column(s).An important difference in the implementation of the UNIQUE constraint is <strong>Oracle</strong> allowsmultiple rows with NULL values in all the columns making up the unique constraint,whereas SQL Server allows only one row to have a NULL value <strong>for</strong> the UNIQUE column.In <strong>Oracle</strong>, the UNIQUE, PRIMARY KEY, and FOREIGN KEY constraints can be acomposite of up to 32 columns, while in SQL Server the limit is 16.Unique constraints can be created using Enterprise Manager as well as T-SQLstatements. To create a UNIQUE constraint using Enterprise Manager, follow these steps:1. In the Table Designer, click the Table and Index Properties button.2. Select the Indexes/Keys tab and click New. A system-assigned index nameappears with the column name, column order, index filegroup, and fill factor filled inusing defaults. You will need to replace these default values with your own.3. Enter the name of the new index in the Index name text box and select thecolumns to be included in the constraint in the correct order in the grid.4. Check the Create UNIQUE check box and select the Constraint radio button.5. Check the Create as CLUSTERED box if a clustered index is to be used toen<strong>for</strong>ce the constraint. If a nonclustered index is chosen, a filegroup can bespecified <strong>for</strong> the index. Because only a single clustered index can be created on atable, and the filegroup cannot be changed from the primary filegroup.6. The equivalent of <strong>Oracle</strong>'s PCTFREE can be specified <strong>for</strong> the index that will becreated to en<strong>for</strong>ce the constraint in the Fill Factor box.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 115 To create a UNIQUE constraint using T-SQL, use the following syntax:The only syntactic difference in the UNIQUE constraint definition between <strong>Oracle</strong> andSQL Server is with the USING INDEX clause used to define the index that en<strong>for</strong>ces theconstraint. The USING INDEX clause of <strong>Oracle</strong> has an equivalent in SQL Server and canbe used with both column and table constraints. The syntax <strong>for</strong> table constraint isdescribed in Table 6.14.Table 6.14: SQL Statements <strong>for</strong> Defining UNIQUE Constraints in <strong>Oracle</strong> andSQL Server<strong>Oracle</strong>SQL ServerCREATE TABLE table_nameCREATE TABLE table_name((column_name datatype,column_name datatype,…,…,[ CONSTRAINT constraint_name ] [ CONSTRAINT constraint_name ]UNIQUE ( column_name [, …] ) UNIQUE [ CLUSTERED | NONCLUSTERED ][ USING INDEX [ TABLESPACE( column_name [, …] )tablespace_name ][ WITH FILLFACTOR = fillfactor ][ storage_definition ] ][ ON FILEGROUP { filegroup |DEFAULT } ]Primary Key ConstraintPRIMARY KEY constraints have all the characteristics of UNIQUE constraints, with theadditional restriction that all primary key columns be NOT NULL. <strong>Oracle</strong> creates aUNIQUE index and a NOT NULL constraint to implement PRIMARY KEY constraints.With <strong>Oracle</strong> 9i, an existing non-unique index may be used to en<strong>for</strong>ce the primary keyconstraint. In SQL Server, if a clustered index does not already exist on the table, or anonclustered index is not explicitly specified, a unique, clustered index is created toen<strong>for</strong>ce the PRIMARY KEY constraint. The following procedures demonstrate that it is fareasier to use T-SQL than Enterprise Manager when it comes to creating a PRIMARYKEY constraint. To create a primary key constraint using Enterprise Manager, follow thesesteps:1. In the Table Designer, click and select the colum n(s) that are part of the primarykey (use the Ctrl key <strong>for</strong> this).2. Right-clic k anywhere along the selected column(s) and click Set Primary Key. Acheck mark appears next to the Set Primary Key option.3. A unique clustered in dex using the naming convention PK_table_name isautomatically created by the system.4. The name and properties of the index can be changed from those assigned by thesystem through the Indexes/Keys pane of the Table and Index Propertieswindow. To create a primary key constraint using T-SQL, use the following syntax:<strong>Oracle</strong> and SQL Server differ only in the USING INDEX part of the PRIMARY KEYconstraint syntax. The syntax differs from the UNIQUE constraint definition only in theUNIQUE keyword being replaced with PRIMARY KEY. In both <strong>Oracle</strong> and SQL Server, aNOT NULL constraint is added by the system <strong>for</strong> all primary key columns when one is notexplicitlyspecified.

116 Developing: Databases — <strong>Migrating</strong> SchemasThe CREATE TABLE syntax in Table 6.15 is <strong>for</strong> defining primary key constraints and itsassociated index.Table 6.15: SQL Statements <strong>for</strong> Defining PRIMARY KEY Constraints in <strong>Oracle</strong>SQL Server<strong>Oracle</strong>SQL ServerCREATE TABLE table_nameCREATE TABLE table_name((column_name datatype,column_name datatype,…,…,[ CONSTRAINT constraint_name ][ CONSTRAINT constraint_name ]PRIMARY KEY ( column_name [, …] ) [ PRIMARY KEY [ CLUSTERED |USING INDEX [ TABLESPACENONCLUSTERED ] ( column_name [, …] )tablespace_name ] [ storage specs ] ] [ WITH FILLFACTOR = fillfactor ] [ ONFILEGROUP { filegroup | DEFAULT } ]andForeign Key ConstraintA <strong>for</strong>eign key constraint en<strong>for</strong>ces the rule that a non-null value in one or more columns ofa table (child) must exist in a corresponding set of columns in the same (self-referential)or another (parent) table. The referenced key columns must possess a primary key orunique key index on them.The number and data types of columns specified in the FOREIGN KEY clause shouldmatch the corresponding columns of the referenced table. FOREIGN KEY constraints inSQL Server have a restriction of not being able to cross database boundaries. In thecase where <strong>for</strong>eign key constraints existing between different schemas of a source<strong>Oracle</strong> database are migrated to separate databases in SQL Server, the constraints willhave to be replaced with triggers. In <strong>Oracle</strong>, the ON DELETE clause is used to specifythe actions that will automatically be undertaken if a parent row is deleted. Additionally,SQL Server has the ON UPDATE clause <strong>for</strong> handling updates to the parent rows.Table 6.16 shows the availability of various control actions using these clauses in <strong>Oracle</strong>and SQL Server:Table 6.16: Functionality Available in <strong>Oracle</strong> and SQL Server with Respect toForeign Key ConstraintOperation Action <strong>Oracle</strong> SQL ServerON DELETE SET NULL Yes NoON DELETE CASCADE Yes YesON DELETE NO ACTION Yes YesON UPDATE CASCADE No YesON UPDATE NO ACTION No YesNote In <strong>Oracle</strong>, the default of NO ACTION (restrict) is assumed only by the absence ofan O N DELETE { SET NULL | CASCADE } clause in the definition. In SQL Server, thedefault is NO ACTION <strong>for</strong> both operations. To mimic the action of SET NULL, it has tobe handled programmatically in the application using an appropriate SQL statement.Foreign key constraints can be created in SQL Server usingEnterprise Manager and T-SQL.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 117 To create a <strong>for</strong>eign key constraint using Enterprise Manager, follow thesesteps:1. Right-click the table name on the table list, click Design Table, and then clickTable and Index Properties.2. Select the Relationships tab and click New.3. A new relationship is created with a default name and current table selected in theForeign key table drop-down list. Type in or select (from drop-down list) theappropriate columns involved in the current table (child table). Also select theappropriate table <strong>for</strong> the Parent key table and its parent columns.4. Select appropriate behaviors <strong>for</strong> the trigger in the check boxes at the bottom of thescreen. The important behaviors are Check existing data on creation andEn<strong>for</strong>ce relationship <strong>for</strong> INSERTs and UPDATEs. To create a <strong>for</strong>eign key constraint using the Database Diagram Wizard, followthese steps:1. Expand Server, then Databases, then target database.2. Right-click Diagrams and click New Database Diagram.3. The wizard will lead you through adding the tables to be included in the diagram.See Figure 6.7.Figure 6.7Using Database Diagram Wizard <strong>for</strong> creating referentials4. To add a relationship, select the <strong>for</strong>eign key column of the child table, and drag it tothe primary or unique key column of the parent table.5. A pop-up dialog will appear with columns filled in based on the columns selectedinthe drag and drop. The actions need not be precise because in<strong>for</strong>mation such as

118 Developing: Databases — <strong>Migrating</strong> Schemasname, primary key, and <strong>for</strong>eign key columns, can be modified be<strong>for</strong>e saving. SeeFigure 6.8.Figure 6.8Choosing the right relationship properties To create a <strong>for</strong>eign key constraint using T-SQL, use the following syntax:Table 6.17 contains the syntax to add <strong>for</strong>eign key constraints with the actions of ONDELETE and also the ON UPDATE statement, which do es not exist in <strong>Oracle</strong>.T able 6.17: SQL Statements <strong>for</strong> Defining FOREIGN KEY Constraints in <strong>Oracle</strong>SQL ServerOperation <strong>Oracle</strong> SQL ServerON DELETECREATE TABLEtable_ nameCREATE TABLEtable_name(…,(…,column_name datatype,…,[ CONSTRAINTconstraint_name ]FOREIGN KEY(column_name [,…]REFERENCES[schema.]ref_table_name(ref_column_name[, …])ON DELETE { SET NULL |column_name datatype,…,[ CONSTRAINTconstraint_name ]FOREIGN KEY(column_name [,…]REFERENCESref_table_name(ref_column_name[, …])ON DELETE { CASCADE |

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 119Operation <strong>Oracle</strong> SQL ServerON UPDATECASCADE }NO ACTION}CREATE TABLEtable_name(…,column_name datatype,…,[ CONSTRAINTconstraint_name ]FOREIGN KEY(column_name [,…]REFERENCESref_table_name(ref_column_name[, …])ON UPDATE { CASCADE |NO ACTION}TriggersTriggers are used to en<strong>for</strong>ce more complex business rules than can be en<strong>for</strong>ced usingconstraints. Triggers are stored procedures that are implicitly executed when certain datamodification (using data manipulation language statements, also known as DML) isper<strong>for</strong>med against tables and views. In <strong>Oracle</strong>, there can be up to twelve combinations oftrigger executions (actions) based on:● DML operation: INSERT, UPDATE, DELETE● Timing: BEFORE, AFTER● Level: ROW, STATEMENTTable 6.18 evaluates SQL Server support <strong>for</strong> the <strong>Oracle</strong> trigger functionality.Table 6.18: Functionality of <strong>Oracle</strong> Triggers Mapped to SQL ServerTrigger Feature <strong>Oracle</strong> SQL ServerDML – INSERT Yes YesDML – UPDATE Column/Row RowDML – DELETE Yes YesTiming – BEFORE Yes Yes (INSTEAD OF)Timing – AFTER Yes YesLevel Row/Statemen tRowViews – INSTEAD OF Yes YesMultiple triggers per action Yes Yes (first/last specified)The SQL Server INSTEAD OF triggers are equivalent to <strong>Oracle</strong>’s BEFORE triggers.When migrating triggers from <strong>Oracle</strong>, the only drawback is that SQL Server does notsupport statement-level triggers. However, there are two pseudo-tables, inserted anddeleted, that are populated during the trig ger execution and which can be used tosimulate statement-level operations. These insertedand deleted pseudo tables aresimilar to the :old and :new pseudo-rows in <strong>Oracle</strong> and are populated with all (multiple)rows affected by the trigger execution. The SQL Server deleted and inserted pseudotablesare available by default and are not specified as part of the trigger definition. In

120 Developing: Databases — <strong>Migrating</strong> Schemas<strong>Oracle</strong>, the pseudo-rows have to be defined in the trigger using the REFERENCINGclause.Note This section is concerned only with creation of the trigger object. A detaileddiscussion on trigger logic (code) and its migration is found in Chapter 11, "Developing:Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL" under the "<strong>Migrating</strong> the DataAccess" section.When multiple triggers exist on a table <strong>for</strong> the same action, <strong>Oracle</strong> does not guaranteeany particular order of execution of multiple triggers. SQL Server has the capability tospecify which trigger should be fired be<strong>for</strong>e (first) and a fter (last) all other triggers usingthe system stored pr ocedure sp_ settriggerorder. This feature has been found useful ine liminating some of the complexities in the code found in <strong>Oracle</strong> triggers to manage thes equence of events.Triggers can be defined on tables either using Enterprise Manager or using T-SQL. To create a trigger using Enterprise Manager, followthese steps:1. In the Enterprise Manager, expand Server, then Databases, then targetdatabase, and then Tables.2. Right-click the table nam e on the table list, click All Tasks, and then click ManageTriggers. Or, click the Trigge rs button in the Table Designer.3. Type in the trigger text using the provided template.4. Click Apply if m ore than one trigger is to be created, or OK to save all changesand close the dialog box. To create a trigger using T-S QL, use the following syntax:Table 6.19 compares the commonly used functionality of the trigger definition CREATETRIGGER statement in <strong>Oracle</strong> and SQL Server.Table 6.19: SQL Statements <strong>for</strong> Creating Triggers in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong>CREATE TRIGGER trigger_name{ BEFORE | AFTER | INSTEAD OF } { {INSERT [ OR ] | DELETE [ OR ] |UPDATE [ OF column_name [, …] ] } }ON table_nameREFERENCING [OLD AS :old] [NEW AS:new][ FOR EACH ROW ]WHEN ( condition )Pl/ sql_blockSQL ServerCREATE TRIGGER trigger_nameON table_name | view_name{ { FOR | AFTER | INSTEAD OF } { [INSERT ] [ , ] [ UPDATE ] [ , ] [DELETE ] }AS[ { IF UPDATE ( column_name )[ { AND | OR } UPDATE ( column_name) ] [ ...n ] |IF ( COLUMNS_UPDATED ( ) {bitwise_operator } updated_bitmask){ comparison_ operator }column_bitmask [ ...n ] } ]sql_statement [ ...n ]}}

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 121IndexesThere are two major categories of indexes in <strong>Oracle</strong>: B-tree indexes and Bitmapindexes. All other indexes are variations of these two basic types to provide additionalfeatures. Table 6.20 provides a quick comparison of the indexing schemes available in<strong>Oracle</strong> and SQL Server:Table 6.20: Indexing Schemes Available in <strong>Oracle</strong> and SQL ServerIndex Scheme <strong>Oracle</strong> SQL ServerB-tree — Unique Yes YesB-tree — Non-unique Yes YesB-tree — Composite Yes (32 columns) Yes (16 columns)B-tree — Ascending Yes YesB-tree — Descending Yes YesB-tree — Cluster Yes NoB-tree — Reverse Key Yes NoB-tree — Key Compressed Yes NoB-tree — Function-based Yes NoB-tree — Index-Organized YesYes (Clustered)TableB-tree — Partitioned Yes NoBitmap Yes (30 columns) NoBitmap — Join Yes NoB-Tree IndexesSQL Server offers two types of indexes: clustered and nonclustered. Both these typesare based on the B-tree data structure. Hence assumptions can be drawn as to theirper<strong>for</strong>mance in the two systems. An important difference between the twoimplementations is <strong>Oracle</strong> does not index rows when all the key columns have null valuesin them, while SQL Server does.Both <strong>Oracle</strong> and SQL Server support the following basic versions of the B-tree index:● Comp osite. <strong>Oracle</strong> allows indexes with up to 32 columns, whereas SQL Serverallows up to 16 columns. While indexes with 16 or more columns are rare, thenumber of columns will have to be trimmed down if such indexes were to bemigrated to SQL Server.● Unique. Unique indexes are used to en<strong>for</strong>ce PRIMARY KEY and UNIQUEconstraints. Even though nulls cannot be compared (nor considered equal) <strong>for</strong>sake of uniqueness, when two rows are identical, null values are considered asidentical. In SQL Server, primary key constraints cannot have null values, whereasunique indexes allow one row with null value. For more in<strong>for</strong>mation, refer to the"Unique Constraints" section earlier in this chapter.● Non-unique. This is the basic <strong>for</strong>m of the B-tree or nonclustered index, where keyvalues can be repeated.● Ascending. The key values are sorted and stored in ascending order.● Descending. The key values are sorted and stored in descending order.The following list provides variations of the B-tree index, implemented with a modificationto the basic B-tree structure, that provide a specific feature:

122 Developing: Databases — <strong>Migrating</strong> Schemas●●●●●●Cluster indexes. Such indexes can be found in <strong>Oracle</strong> on clustered tables(clusters). Clustered tables are not supported by SQL Server and neither arecluster indexes.Index-organized tables. The clustered indexes in SQL Server are similar to theindex organized tables. Refer to the discussion under the "Tables" section earlier inthis chapter.Reverse key indexes. <strong>Oracle</strong> developed these indexes to reduce contention <strong>for</strong>index blocks by indexes on columns that have sequential values that are writtenalmost simultaneously. This is achieved by reversing the bytes in the key value toproduce non-sequential numbers. This indexing scheme is not available inSQL Server. The reverse key index is useful in <strong>Oracle</strong> Real Application Cluster(RAC) implementations, and there is no disadvantage in migrating such indexes toclustered or nonclustered indexes.Partitioned indexes. In <strong>Oracle</strong>, B-tree indexes can be created that are local to thepartition or global to the entire table (partitioned or non- partitioned). This feature isnot available in SQL Server and should be replaced by clustered or nonclusteredindexes.Key compressed index. In key compression, the leading subsets of a key can becompressed in a manner similar to clustering by storing the leading subset onlyonce <strong>for</strong> repeating values. SQL Server does not support key compression.Function-based index. In <strong>Oracle</strong>, expressions in the WHERE clause that containfunctions do not use indexes as an access path. To overcome this disadvantage,indexes can be created by applying the function to compute the value of theexpression and storing it in an index. For example, if the column part_name isaccessed using the expression UPPER(part_name), a function-based index can bedefined on UPPER(part_name). SQL Server does not support function-basedindexes. There is no other index type in SQL Server that can provide similarfunctionality.Bitmap IndexThe bitmap indexes are specia lly designed <strong>for</strong> improving the retrieval of data based oncolumns with very low cardinality. Becaus e maintenance of the bitmap indexes is veryexpensive, their utility is restric ted to Data Warehouses and DSS systems where there isvery low or zero update activity.Bitmap indexes are not available in SQL Server and cannot be substituted with B-treeindexes.I n SQL Server and versions of <strong>Oracle</strong> be<strong>for</strong>e 9i, indexes are used only when the leadingsubset of key values are involved. In <strong>Oracle</strong> 9i, <strong>Oracle</strong> introduced the concept of fastindex scan, whereby the entire index is scanned <strong>for</strong> matching values in the non-leadingkeys by skipping the leading key columns. In SQL Server, additional indexes have to becreated <strong>for</strong> the non-leading columns to provide access paths similar to <strong>Oracle</strong>. Thisrequirement is not documented inside the database and is dependent on the SQLstatements used in applications. These situations can only be discovered by profiling theapplication during testing.The various types of indexes can be created using Enterprise Manager, the Create IndexWizard, or T-SQL.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 123 To create an index using Enterprise Manager, follow these steps:The steps <strong>for</strong> creating an index are very similar to that described <strong>for</strong> UNIQUE key. Creationof a non-unique, nonclustered index is demonstrated here.1. Expand Server, then Databases, then target database, and then Tables.2. Right-click the table nam e on the table list, click Design Table, and then clickTable and Index Properties.3. Select the Indexes/Keys tab and click New.4. Enter the name of the new ind ex in the Index name text box. Insert the columns orthe index in grid along with the required sort order fo r the column.5. Uncheck the Create UN IQUE check box to specify a non-unique index.6. Select the target filegroup fro m the Index Filegroup drop-down list.7. Click the desired value <strong>for</strong> Fill factor (equivalent of PCTFREE). To create an index using the Create Index Wizard, follow these steps:1. Expand a server group, and then expand the server in which to create the index.2. On the Tools menu, click Wizards.3. Expand Database.4. Double-click Create Index Wizard.5. Complete the steps in the wizard To create an index using T-SQL, use the following syntax:Table 6.21 shows the syntax of the CREATE INDEX statement <strong>for</strong> the features andfunctionality discussed here.Table 6.21: SQL statements available <strong>for</strong> Creating Indexes in <strong>Oracle</strong> andSQL Server<strong>Oracle</strong>CREATE [UNIQUE | BITMAP ]INDEX index_nameON table_name ( column_name[ ASC | DESC ] [, …] )[ physical_attributes ][ { COMPRESS | NOCOMPRESS }prefix_length ][ REVERSE ][ TABLESPACE tablespace_name ][ storage_description ]SQL ServerCREATE [ UNIQUE ] [ CLUSTERED |NONCLUSTERED ] INDEX index_nameON table_name ( column_name[ ASC | DESC ] [, … ] )[ WITH index_options ][ ON filegroup ]ViewsVie ws are used in <strong>Oracle</strong> and SQL Server to hide query complexity and encourage queryreuse. Both <strong>Oracle</strong> and SQL Server have added features, such as updateability andinde xes to views, to improve their utility and per<strong>for</strong>mance.

124 Developing: Databases — <strong>Migrating</strong> SchemasTable 6.22 compares the availability of the various types of views in <strong>Oracle</strong> andSQL Server.Table 6.22: Types of Views Available in <strong>Oracle</strong> and SQL ServerView Type <strong>Oracle</strong> SQL ServerSimple Views Yes YesJoin Views Yes YesPartitioned Views Yes YesRead-only Views Yes NoUpdateable Views Yes YesInline Views Yes YesObject Views Yes NoThe following are the various types of views available in <strong>Oracle</strong> and the support <strong>for</strong> themin SQL Server:● Simple views. This view query is based on a single table and their migration istrivial.● Join views. This view query is based on more than one table. The join viewsavailable in SQL Server are less restrictive than their <strong>Oracle</strong> counterparts in theiruse of aggregate functions in the query. Hence migrating them from <strong>Oracle</strong> toSQL Server should not pose any problems. When a view is defined with an outerjoin and is queried with a qualification on a column from the inner table of the outerjoin, the results from SQL Server and <strong>Oracle</strong> can differ.● Partitioned views. This view query provides a union of partitions of data indifferent tables (regular non-partitioned tables). Use of partitioned views wascommon in <strong>Oracle</strong> be<strong>for</strong>e the introduction of partitioned tables in <strong>Oracle</strong> 8.SQL Server supports the entire range of features that are available in <strong>Oracle</strong> withrespect to partitioned views.● Read-only views. This view query with the WITH READ ONLY clause specified tocurb update activity against the base tables of the view. SQL Server does not havean equivalent <strong>for</strong> this feature. When migrating a read-only view, care has to betaken to ensure that only SELECT privileges are granted to the users.● Updatable views. These are simple, join, or partitioned views against which DMLstatements can be executed, subject to certain restrictions. In SQL Server, therestrictions can be bypassed (except the use of aggregate functions) by definingINSTEAD OF triggers on the views. The WITH CHECK OPTION clause preventsmodifications to data that violate the criteria in the WHERE clause of the viewquery. DML statements on join views can modify data only in one base table.● Inline views. An inline view is a subquery that is used like a view in the FROMclause of SQL statements. SQL Server fully supports their definition.● Object views. Object views are virtual object tables that can be used tomanipulate object data types as well as relational data cast as objects. Objectviews are not available in SQL Serverand should be recreated (flattened) asregular views.● Indexed views. <strong>Oracle</strong> does not support creation of indexes on views. However,UNIQUE, PRIMARY KEY, and FOREIGN KEY constraints can be defined on viewswhich indirectly create indexes. These constraints are a subset of those availablewith tables and work similarly. SQL Server allows creation of indexes. However thefirst index has to be a unique clustered index. Additional nonclustered indexes canthen be created. Thus, SQL Server can support the migration of indexed views.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 125Views can be created using Enterprise Manager, the Create View Wizard, or T-SQL. To create a view using Enterprise Manager, follow these steps:1. Open Enterprise Manager, expand Server, then Databases, and then the targetdatabase.2. Right-click Views and click New View.3. The view can be created using the dia gram and grid panes (top two areas) or byentering the view query in the SQL pa ne (SELECT area). See Figure 6.9.Figure 6.9Using the View Designer of Enterprise Manager To create a view using the Create View Wizard, follow these steps:1. Expand a server group and then expand the server in which to create the view.2. On the Tools menu, click Wizards.3. Expand Database.4. Double-click Create View Wizard.5. Complete the steps in the wizard.

126 Developing: Databases — <strong>Migrating</strong> Schemas To create a view using T-SQL, use the following syntax:Table 6.23 offers a comparison of the CREATE VIEW statements in <strong>Oracle</strong> andSQL Server.Table 6.23: SQL Statement <strong>for</strong> Creating Views in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong>CREATE [OR REPLACE] [FORCE |NO FORCE] VIEW [schema.]view_nameSQL ServerCREATE VIEW [owner.]view_namename [,…] ) ][ ( column_[ ( column_alias [ inline_constraint ] [,…] [, AS select_statementout_of_line_constraint ] ) ]AS select_statement[ WITH READ ONLY ][ [ WITH CHECK OPTION ] [CONSTRAINT constraint_name ] ][ WITH CHECK OPTION ]In O racle, views can be created without permissions on the base objects, or even withoutthe base objects existing, by using the FORCE keyword. This is not allowed inSQL Server. SQL Server also does not allow ORDER BY and GROUP BY clauses in theview definition.Note When a view is created in <strong>Oracle</strong> using an asterisk (*) in the SELECT clause, theasterisk is expanded to the actual column names in the definition of the view.SQ L Server retains the exact definition used in the DDL. <strong>Oracle</strong> does the same thingwhen an asterisk (*) is not used. While converting from <strong>Oracle</strong> to SQL Server, the viewdefinition may be changed back to an asterisk instead of specifying every column.Stored ProgramsOra cle and SQL Server have the capability to store complex business logic (beyondconstraints) inside the database. The code to support such requirements cannot beprovided by SQL because it cannot execute commands based on logical conditions. Italso fails to support looping operations. In spite of recent extensions to SQL, such asinco rporation of a CASE expression, it is still difficult to per<strong>for</strong>m more than one operationbased on a logical condition using these methods. The need to implement controlstructures and programming constructs cannot be met with SQL alone. Hence <strong>Oracle</strong>and SQL Server both offer procedural extensions to SQL, PL/SQL, and Transact-SQL ( T-SQL), respectively, that offer a more complete environment <strong>for</strong> defining stored programs(or subprograms).Stored programs provide modularity (top-down design), encapsulation (logic is hidden),abstraction (black box approach), security (only execute on subprogram), andextensibility (user-defined functionality). Additionally, existence inside the databasepromotes accessibility (available to all users), reuse (available to all database users),speed of execution (stored programs are in compiled <strong>for</strong>m), per<strong>for</strong>mance (handling oflarge amounts of data close to its source), and reduced resource requirements (reducesnetwork bandwidth, memory, and so on because only the results are transported).In <strong>Oracle</strong>, Java can be used to write native stored procedures and user-defined functions.A PL/SQL procedure can also call external procedures or functions written in the Cprogramming language and stored in a shared library.In <strong>Oracle</strong>, there are four types of stored programs: functions, procedures, packages, andtriggers. These objects are very similar in construction, functionality,and usage to those

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 127used in SQL Server. Hence the migration of their structures is trivial. However, becauseof the vast difference between the syntax in the languages (PL/SQL and T-SQL) used inthese objects, the migration of the embedded code is far from trivial.Triggers have already been discussed in this chapter. Functions, procedures, andpackages are covered here.<strong>Oracle</strong> ensures the purity of the actions that are per<strong>for</strong>med inside stored programs.Hence there are no hidden side effects when migrated to SQL Server and you canconcentrate on reproducing the logic using T-SQL.Here are a few points that concern all types of stored programs:● Overloading. SQL Server does not support overloading, and such functions andprocedures will have to be recreated using unique names.● Execution privileges. <strong>Oracle</strong> stored programs can be defined to execute withdefiner-rights (owner) or invoker-rights (user). SQL Server only uses invoker-rights.<strong>Oracle</strong> stored programs that are built on definer-rights architecture can beconverted to SQL Server invoker-rights subprograms by properly qualifying objectsinside stored programs. With invoker rights, the schema name could also bepassed in and SQL dynamically constructed.● Parameters. Both <strong>Oracle</strong> and SQL Server support positional, named, or mixednotation <strong>for</strong> parameters. SQL Server c an handle all the types of para meters thatare found in <strong>Oracle</strong>, including tables.<strong>Oracle</strong> has three parameter modes: IN, OUT, and IN OUT. SQL Server does notallow the IN OUT type of parameters, and this type warrants some rework in theapplication design when migrating. Hence IN OUT parameters will have to bereplaced with two separate IN and OUT parameters. The keyword OUTPUT isused in place of OUT, while the keyword IN does not exist and is implied becauseit is the default mode. Also, even though it is not a good practice, there is norestrictio n on the usage of OUT and IN OUT parameters in <strong>Oracle</strong> functions.Violations of this rule should be trapped and corrected during migration.In <strong>Oracle</strong> and SQL Server, IN parameters can be given default values. If suchparameters are skipped during a call, the default value is applied. In SQL Server,this rule holds <strong>for</strong> stored procedures but not <strong>for</strong> functions. With functions, thekeyword "default" has to be used in the call to the function and cannot be skippedas with stored procedures (which imply the use of the default value).SQL Server parameters are prefixed by the at (@) symbol.● Using same name as system. If the first three characters of the procedure nameare sp_, SQL Server searches the master database <strong>for</strong> the procedure. If noqualified procedure name is provided, SQL Server searches <strong>for</strong> the procedure as ifthe owner name is dbo. To resolve the stored procedure name as a user-definedstored procedure with the same name as a system stored procedure, provide thefully qualified procedure name.Only the migration of the object structure is provided in this chapter. Refer to Chapter 11,"Developing: Applications — <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> a detailed discussion aboutmigrating the embedded PL/SQL code to T-SQL.FunctionsWhile the system provides several built-infunctions, <strong>Oracle</strong> and SQL Server provide thecapability to define custom functions called user-defined functions. These user-definedextensions to SQL always return a result. They are employed primarily in SQLstatements.Functions can be created using Enterprise Manager or T-SQL.

128 Developing: Databases — <strong>Migrating</strong> Schemas To create a function using Enterprise Manager, follow these steps:1. Expand a server group, and then expand a server.2. Expand Databases, and then expand the database in which to create the function.3. Right-click User Defined Functions and select New User Defined Function.4. In the Text box, enter the text of the function. Use TAB to indent the text of afunction.5. To check the syntax, click Check Syntax and OK to create. To create a function using T-SQL, use the following syntax:Functions can be created in SQL Server using the CREATE FUNCTION statement,which is very similar to the one found in <strong>Oracle</strong>, as show in Table 6.24.Table 6.24: SQL Statements <strong>for</strong> Creating Triggers in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong>CREATE OR REPLACE FUNCTION[schema.]function_name[ ({parameter [IN] datatype [=default]} [, …]) ]RETURN scalar_expression{IS | AS}variable_declarationBEGINstatementsRETURN scalar_expressionEXCEPTIONstatementsEND;SQL ServerCREATE FUNCTION [owner.]function_name[ ({@parameter [AS] datatype [ =default ]} [, …]) ]RETURN scalar_expression[ AS ]BEGINvariable_declarationstatementsRETURN scalar_expressionENDStored ProceduresSQL Server has stored procedures that closely resemble <strong>Oracle</strong>. These storedprocedures provide the capability to pass multiple parameters back to the callingenvironment. Another advantage of stored procedures is that they can per<strong>for</strong>m actions inthe database without being tied to a SQL statement.Stored procedures can be created using the Create Stored Procedure Wizard, EnterpriseManager, or T-SQL. To create a view using the Create Stored Procedure Wizard, follow thesesteps:1. Expand a server group and then expand the server in which to create the view.2. On the Tools menu, click Wizards.3. Expand Database.4. Double-click Create Stored Procedure Wizard.5. Complete thesteps in the wizard.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 129 To create a stored procedure using Enterprise Manager, follow these steps:1. Expand a server group, and then expand a server.2. Expand Databases, and then expand the database in which to create the storedprocedure.3. Right-click Stored Procedures and select New Stored Procedure.4. In the Text box, enter the text of the stored procedure. Use TAB to indent the textwithin.5. To check the syntax, click Check Syntax and OK to create. To create a stored procedure using T-SQL, use the following syntax:Both <strong>Oracle</strong> and SQL Server offer the CREATE PROCEDURE statement, which is verysimilar in structure and is shown in Table 6.25.Table 6.25: SQL Statements <strong>for</strong> Creating Procedures in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong>CREATE OR REPLACE PROCEDURE[schema.]procedure_name[ ({parameter [IN|OUT|IN OUT]datatype [= default]} [, …]) ]{IS | AS}variable_declarationBEGINstatementsEXCEPTIONstatementsEND;SQL ServerCREATE PROCEDURE [owner.]procedure_name[ ({@parameter [AS] datatype [ =default ] [OUTPUT]} [, …]) ]ASBEGINvariable_declarationstatementsENDPackagesOne of the main differentiators between stored procedures and packages is the capabilityto declare variables in the package header that act as global variables. SQL Server doesnot have packages, and these have to be replaced with stored procedures. However,SQL Server allows the nesting of procedures, and this capability can be used to simulatethe structure of packages by nesting functions and procedures. Variables can be madeavailable to all the nested functions and procedures by declaring them in the outmost (ormain) procedure. This, however, does not provide database-wide accessibility to thesevariables, a shortcoming which has to be accommodated by migrating the global variablefrom the package to the application code.<strong>Solution</strong>s <strong>for</strong> Objects not Found in SQL ServerSome <strong>Oracle</strong> objects, such as synonyms and sequences, are widely used in <strong>Oracle</strong>applications. However, there is no equivalent object with similar functionality inSQL Server. Finding solutions to implement the logic and functionality around theseobjects in SQL Server is critical to the migration.SynonymsIn <strong>Oracle</strong>, synonyms are aliases <strong>for</strong> tables, views, sequences, functions, procedures, andpackages. The primary purpose of using synonyms is <strong>for</strong> location transparencyandnaming transparency. By creating public synonyms or private synonyms (<strong>for</strong> each user),

130 Developing: Databases — <strong>Migrating</strong> Schemasapplications can be written without schema qualification in the SQL code because thequalifier is defined in the synonyms. The original object names can also be hidden.Synonyms <strong>for</strong> tables are more easily migrated by substituting them with views. Viewsprovide the required location and naming transparency as well. For example, a privatesynonym, CLINTB.DEPT, which connects to the table HR.DEPARTMENT, can ber eplaced in SQL Server by a VIEW as follows:CREATE VIEW CLINTB.DEPT AS SELECT * FROM HR.DEPARTMENTOne of the known drawbacks when creating SELECT * views in <strong>Oracle</strong> is that anychanges that are made to the base table definition in terms of adding, dropping, andrenaming columns are not automatically reflected in the view definition. This is because<strong>Oracle</strong> converts the query piece:SELECT * FROM table_nameintoS ELECT column_name [, …] FROM table_nameConsequently, when a column is added to the base table, the view definition does notchange. Dropping or renaming a column invalidates the view. However, SQL Server doesnot have this problem because the view DDL is stored as it was written, that is, SELECT* FROM table_name.I t is not possible to find an object-based solution <strong>for</strong> synonyms connecting to other typesof objects, such as procedures and sequences. The simplest solution is to qualify theobject schema or owner in the application rather than resolve it at the database loginlevel.The inherent quality of SQL Server in resolution of objects can be used <strong>for</strong> providing asolution. Synonyms are usually employed in situations where there are multiple versionsof the same application being used to support different clients, with each client having itsown schema. The schema that will be used is driven by the user login and not theapplication itself. This can be achieved in SQL Server by setting the default database <strong>for</strong>a user account and giving the login the appropriate privileges at the object level. Thisscheme will work as long as all the objects that will be accessed are in a single databaseand it is set as the default database <strong>for</strong> the user. For more in<strong>for</strong>mation about theseissues, refer to Chapter 7, "Developing: Databases — <strong>Migrating</strong> the Database Users."SequencesIn <strong>Oracle</strong>, sequences are autonomous schema objects that can be used to generatenumbers that are in sequential order. In applications, sequences are commonly used toproduce artificial keys <strong>for</strong> tables which do not have a natural key, or the natural key is toolong. SQL Server does not have an equivalent <strong>for</strong> sequences. However, a SQL Servertable can have columns that are defined with the IDENTITY property, which simulates thebehavior of <strong>Oracle</strong> sequences. The IDENTITY column is an <strong>Oracle</strong> sequence and tablecolumn rolled into one, that is, the column definition includes the sequence definition.The syntax of the SQL Server IDENTITY property isIDENTITY [(seed, increment)]The <strong>Oracle</strong> start with is replaced by the SQL Server seed.The <strong>Oracle</strong> increment by is equivalent to the SQL Server incrementThe <strong>Oracle</strong> maxvalue is provided by the SQL Server column data type.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 131Table 6.26 shows the implementation of the IDENTITY property feature in SQL Serverand what would be the equivalent in <strong>Oracle</strong>.Table 6.26: Implementation of <strong>Oracle</strong> Sequence in SQL Server<strong>Oracle</strong>CREATE SEQUENCE sequence_nameSTART WITH 1 INCREMENT BY 1CREATE TABLE table_name (column1NUMBER DEFAULTsequence_name.NEXTVAl,column2 …);INSERT INTO table_name (column2, …)VALUES ( … )CREATE TABLE table_name (column1NUMBER,column2 …);INSERT INTO table_name (column1,column2, …) VALUES(sequence_name.NEXTVAL, … )SQL Server-CREATE TA BLE table_name (column1NUMBER IDENTITY(1,1),column2 …);INSERT INTO table_name (column2, …)VALUES ( … )CREATE TABLE table_name (column1NUMBER IDENTITY(1,1),column2 …);INSERT INTO table_name (column2, …)VALUES ( … )One of the advantages of sequences being independent objects is that they can be usedto supply a unique identifier across multiple tables. This property of <strong>Oracle</strong> sequences isnot inherent in SQL Server’s IDENTITY property. If an identifier is required to be uniqueacross tables (or even databases across the globe), use the uniqueidentifier data type,which can be populated using the NEWID() function. The IDENTITY column can onlyhandle unique values and hence it cannot support the cycle feature of <strong>Oracle</strong> sequence.A maximum value also cannot be set but can be en<strong>for</strong>ced by choosing an appropriatesized data type <strong>for</strong> the IDENTITY column.Note There is no sufficient in<strong>for</strong>mation inside the <strong>Oracle</strong> database to figure out howand where a sequence is used. Hence the application's documentation, code, ordeveloper will have to be consulted to learn which sequence is used to populate acolumn. This in<strong>for</strong>mation is then used to define an IDENTITY column in that table.Database Links<strong>Oracle</strong> database links are used to <strong>for</strong>m a bridge between databases (instances). Remoteand distributed transactions can be executed against the remote database using thedatabase link. SQL Serverprovides similar functionality under the linked server.

132 Developing: Databases — <strong>Migrating</strong> SchemasTable 6.27 compares some of the characteristics of database links in <strong>Oracle</strong> andSQL Server.Table 6.27: Comparison of Database Links in <strong>Oracle</strong> and SQL ServerAttribute<strong>Oracle</strong>SQL ServerLink Types Public and Private PublicDatabase Types Homogeneous Homogeneous andHeterogeneousCREATE [ PUBLIC ] DATABASELINK [ CONNECT TO {sp_addlinkedserver [ @server= ] 'server'CURRENT_USER | user [ , [ @srvproduct = ]IDENTIFIED BY password } ] 'product_name' ]USING 'connect_string'[ , [ @provider = ]'provider_name' ][ , [ @datasrc = ]'data_source' ][ , [ @location = ] 'location' ][ , [ @provstr = ]'provider_string' ][ , [ @catalog = ] 'catalog'Note The provider_name <strong>for</strong> an OLE DB-based connection to another SQL Server is'SQLOLEDB'.The following example shows the use of sp_addlinkedserver to create a linked server toconnect to another database <strong>for</strong> executing distributed queries:sp_addlinkedserver@server='CORP2',@srvproduct='',@provider='SQLOLEDB',@datasrc='SHUTTLE\CORP2'Sample Schema Object MigrationThe following example illustrates the schema owner and schema objects migration taskof the database migration. The HR schema has been used in this example.1. Create the SQL Server login account (database authenticated).The following commands create a database-authenticated login with name HR.Use MASTEREXEC sp_addlogin@loginame='HR',@passwd='HR',@defdb='HRDATA'2. Create user account in the database.The following commands create a user account <strong>for</strong> the HR login in the HRDATAdatabase in which objects will be created.Use HRDATAEXEC sp_grantdbaccess@loginame='HR',

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 133@name_in_db='HR'3. Gra nt privileges to create objects in the database.Priv ileges can be granted to the schema owner to create objects in a databaseusing either the CREATE permissions or the db_owner fixed database role.a.b.Grant complete authority on the database.The following command can be used to grant the db_owner role:EXEC sp_addrolemember@rolename='db_owner',@membername='HR'Grant privileges to create objects only.The following commands can be executed to only grant permission to createobjects:GRANT CREATE FUNCTION TO HRGRANT CREATE PROCEDURE TO HRGRANT CREATE TABLE TO HRGRANT CREATE VIEW TO HR4. Create sequences.While sequences cannot be migrated to SQL Server, in<strong>for</strong>mation about theseq uences in the <strong>Oracle</strong> database should be extracted first. Because sequencesare migrated to IDENTITY columns in tables, the in<strong>for</strong>mation about sequences isrequired to appropriately define tables (in the next step).The following command extracts the required in<strong>for</strong>mation on sequences.SELECT sequence_name, min_value, max_value, increment_byFROM dba_sequencesWHERE sequence_owner = 'HR'The following output is obtained:SEQUENCE_NAME MIN_VALUE MAX_VALUE INCREMENT_BYDEPARTMENTS_SEQ 1 9990 10EMPLOYEES_SEQ 1 999999999999999999999999999 1LOCATIONS_SEQ 1 9900 100The three sequences in the HR schema are assumed to be used to populate thecolumns DEPARTMENTS.DEPARTMENT_ID, EMPLOYEES.EMPLOYEE_ID andLOCATIONS.LOCATION_ID, respectively.5. Create tables.There are two options <strong>for</strong> how to migrate tables. Option one is to create tables in aspecific order based on the <strong>for</strong>eign key constraints (parent tables first). Option twois to create tables in any order, leaving out the <strong>for</strong>eign key constraints and thenadding them after all the tables have been created.a. Obtain a list of tables.If option one is followed, the dependenci es between tables and the right orderin which to create the tables is required. There are several scripts available(mostly PL/SQL-based) to produce such a list. Tables without anydependencies <strong>for</strong>m the first level, and other levels are <strong>for</strong>med based on thenesting of the dependencies.Note None of the available scripts will work when there are interdependenciesbetween tables that <strong>for</strong>m a closed loop. The following script shows suchcircular dependencies thatmake these scripts not viable.

134 Developing: Databases — <strong>Migrating</strong> SchemasSELECT table_name parent_table_name, NULL child_table_nameFROM dba_tables utWHERE owner = 'HR'AND NOT EXISTS (SELECT 'x'FROM user_constraints ucWHERE constraint_type = 'R'AND ut.table_name = uc.table_name)UNION ALLSELECT p.table_name parent_table_name,c.table_name child_table_nameFROM dba_constraints p, dba_constraints cWHERE p.owner = c.ownerAND p.owner = 'HR'AND p.constraint_type IN ('P','U')AND c.constraint_type = 'R'AND p.constraint_name = c.r_constraint_nameNote In the following output there is a parent-child relationship betweenEMPLOYEES and DEPARTMENTS in both directions that creates the loop.PARENT_TABLE_NAME CHILD_TABLE_NAMEJOBSREGIONSREGIONSCOUNTRIESLOCATIONSDEPARTMENTSEMPLOYEESDEPARTMENTSDEPARTMENTS EMPLOYEESJOBSEMPLOYEESEMPLOYEESEMPLOYEESJOBSJOB_HISTORYEMPLOYEESJOB_HISTORYDEPARTMENTS JOB_HISTORYCOUNTRIESLOCATIONSTo implement option two, first obtain a list of all tables that need to be migratedusing the following command:SELECT table_name, tablespace_name, iot_typeFROM dba_tablesWHERE owner = 'HR'The output obtained is:TABLE_NAMECOUNTRIESTABLESPACE_NAMEIOT_TYPEIOTDEPARTMENTS EXAMPLEEMPLOYEES EXAMPLEJOBSEXAMPLEJOB_HISTORY EXAMPLELOCATIONS EXAMPLEREGIONS EXAMPLE

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 135b.Extract DDL along with constraints.There are several scripts and tools thattable object.can be used to extract the DDL <strong>for</strong> theFor an <strong>Oracle</strong> 9i database, the <strong>Oracle</strong>-supplied package DBMS_METADATAcan be used. First, execute the following in SQL*Plus to define the output style.set pagesize 0set long 10000EXECUTEDBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM,'STORAGE', FALSE);EXECUTE DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'TABLESPACE', TRUE);EXECUTE DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'SQLTERMINATOR', TRUE);EXECUTE DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'CONSTRAINTS', TRUE);EXECUTE DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'REF_CONSTRAINTS', TRUE);EXECUTE DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'CONSTRAINTS_AS_ALTER', TRUE);Then execute DBMS_METADATA.get_ddl <strong>for</strong> each of the tables. The followingtwo examples show how to extract the DDL <strong>for</strong> entire tables using thisprocedure:SELECT dbms_metadata.get_ddl('TABLE', 'COUNTRIES', 'HR')FROM DUAL;The output is as follows:CREATE TABLE "HR"."COUNTRIES"("COUNTRY_ID" CHAR(2) CONSTRAINT "COUNTRY_ID_NN" NOT NULL ENABLE,"COUNTRY_NAME" VARCHAR2(40),"REGION_ID" NUMBER,CONSTRAINT "COUNTRY_C_ID_PK" PRIMARY KEY ("COUNTRY_ID") ENABLE) ORGANIZATION INDEXNOCOMPRESS PCTFREE 10 INITRANS 2 MAXTRANS 255 LOGGINGTABLESPACE "EXAMPLE"PCTTHRESHOLD 50;ALTER TABLE "HR"."COUNTRIES" ADD CONSTRAINT"COUNTR_REG_FK" FOREIGN KEY ("REGION_ID")REFERENCES "HR"."REGIONS" ("REGION_ID") ENABLE;Execute the following command to obtain the definition of the LOCATIONStable.SELECT dbms_metadata.get_ddl('TABLE', 'LOCATIONS', 'HR')FROM DUAL;The output returned is:CREATE TABLE "HR"."LOCATIONS"("LOCATION_ID" NUMBER(4,0),"STREET_ADDRESS" VARCHAR2(40),"POSTAL_CODE" VARCHAR2(12),"CITY" VARCHAR2(30) CONSTRAINT "LOC_CITY_NN" NOT NULL ENABLE,"ST ATE_PROVINCE"VARCHAR2(25),"COUNTRY_ID" CHAR(2)) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGINGTABLESPACE "EXAMPLE" ;

136 Developing: Databases — <strong>Migrating</strong> SchemasCREATE UNIQUE INDEX "HR"."LOC_ID_PK" ON"HR"."LOCATIONS" ("LOCATION_ID")PCTFREE 10 INITRANS 2 MAXTRANS 255 NOLOGGINGTABLESPACE "INDX" ;ALTER TABLE "HR"."LOCATIONS" ADD CONSTRAINT"LOC_ID_PK" PRIMARY KEY ("LOCATION_ID")USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 NOLOGGINGTABLESPACE "INDX" ENABLE;ALTER TABLE "HR"."LOCATIONS" ADD CONSTRAINT"LOC_C_ID_FK" FOREIGN KEY ("COUNTRY_ID")REFERENCES "HR"."COUNTRIES" ("COUNTRY_ID") ENABLE;c. Convert the extracted <strong>Oracle</strong> DDL to SQL Server syntax.In this step, the table DDL is converted along with constraint and indexdefinitions. Foreign key constraints are handled separately in the next step.Create clustered indexes be<strong>for</strong>e creating any non-clustered indexes. Ifclustered indexes are planned <strong>for</strong> a table, defer creation of nonclusteredindexes (as part of PRIMARY KEY or UNIQUE constraint definition) during thetable creation in this step.The first table in the example, COUNTRIES, is an index-organized table. ForSQL Server, it is converted into a heap with a clustered index on the primarykey, COUNTRY_ID.Note In <strong>Oracle</strong>, there is a single datatype of the number variety which isconstrained with appropriate scale. While converting to SQL Server, the datatype which is closest in scale needs to be used, as has been demonstrated inthe example.The following commands are used to create the COUNTRIES andLOCATIONS tables respectively.CREATE TABLE HR.COUNTRIES(COUNTRY_ID CHAR(2) CONSTRAINT NN_COUNTRY_ID NOT NULL,COUNTRY_NAME VARCHAR(40),REGION_ID NUMERIC,CONSTRAINT PK_COUNTRY_C_ID PRIMARY KEY CLUSTERED (COUNTRY_ID)ON HR_INDX)CREATE TABLE HR.LOCATIONS(LOCATION_ID SMALLINT NOT NULL,STREET_ADDRESS VARCHAR (40),POSTAL_CODE VARCHAR(12),CITY VARCHAR(30) CONSTRAINT NN_LOC_CITY NOT NULL,STATE_PROVINCE VARCHAR(25),COUNTRY_ID CHAR(2))ALTER TABLE HR. LOCATIONS ADD CONSTRAINTPK__ID PRIMARY KEY NONCLUSTERED (LOCATION_ID)ON HR_INDX

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 1376.d.Create the <strong>for</strong>eign key constraints.After all the tables have been created, the <strong>for</strong>eign key constraints can becreated in any order.The following commands create <strong>for</strong>eign keys on the COUNTRIES andLOCATIONS tables.ALTER TABLE HR.COUNTRIES ADD CONSTRAINTFK_COUNTR_REG FOREIGN KEY (REGION_ID)REFERENCES HR.REGIONS (REGION_ID);ALTER TABLE HR.LOCATIONS ADD CONSTRAINTFK_LOC_C_ID FOREIGN KEY (COUNTRY_ID)REFERENCES HR.COUNTRIES (COUNTRY_ID);e. Extract and migrate the table comments.The following command can be used to extract comments in tables in the HRschema.SELECT table_name, commentsFROM dba_tab_commentsWHERE owner = 'HR'AND comments IS NOT NULLThe output returned contains the comments <strong>for</strong> the tables in the HR schema,such as COUNTRIES, DEPARTMENTS, EMPLOYEES, JOBS,JOB_HISTORY and LOCATIONS. The output can then be copied into thestatements <strong>for</strong> adding comments to tables in SQL Server.The following is an example of the use of the sp_addextendedpropertyprocedure to add a comment on the COUNTRIES table.sp_addextendedproperty 'comment', 'country table. Contains 25 rows.References with locations table.', 'user', HR, 'table', countriesf. Extract and migrate the column comments:SELECT table_name, column_name, commentsFROM dba_col_commentsWHERE owner = 'HR'AND comments IS NOT NULLThe output contains the column level comments.The following is an example of the use of the sp_addextendedpropertyprocedure to add a comment on the REGION_ID column of the COUNTRIEStable.sp_addextendedproperty 'comment', 'Region ID <strong>for</strong> the country. Foreignkey to region_id column in the departments table.' , 'user', hr,'table', countries, 'column', region_idCreate triggers.This step demonstrates how to migrate the table triggers from <strong>Oracle</strong> toSQL Server. The logic (code) that is embedded in the triggers is not discussedhere. For more in<strong>for</strong>mation, refer to the "<strong>Migrating</strong> the Data Access" section inChapter 11, "Developing: Databases — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL."SELECT table_name, 'CRE ATE TRIGGER ' || description headerFROM dba_triggersWHERE owner = table_ownerAND table_owner = 'HR'AND base_object_type = 'TABLE'TABLE_NAME HEADEREMPLOYEES CREATE TRIGGER secure_employees

138 Developing: Databases — <strong>Migrating</strong> SchemasBEFORE INSERT OR UPDATE OR DELETE ON employeesEMPLOYEES CREATE TRIGGER update_job_historyAFTER UPDATE OF job_id, department_id ON employeesFOR EACH ROWThe equivalent syntax <strong>for</strong> SQL Server can be generated with the aid of Table 6.24.The commands <strong>for</strong> creating the secure_ employees and update_job_historytriggers will convert as:7.CREATE TRIGGER secure_employeesON employeesINSTEAD OF INSERT, UPDATE, DELETEAS…GOCREATE TRIGGER update_job_historyON employeesAFTER UPDATEAS…GOIF (UPDATE(job_id) or UPDATE(department_id))Create indexes.All indexes related to constraints should have been created in Substep 5.b. Thisstep covers the indexes that are not related to any constraints.The following query can be used to retrieve in<strong>for</strong>mation on indexes in <strong>Oracle</strong> thatare not related to any constraints. This query will work only in <strong>Oracle</strong> 9i becausethe data dictionary be<strong>for</strong>e this release of <strong>Oracle</strong> does not have the columns used inthis query.SELECT i.table_name, i.index_name, c.column_name, i.uniqueness,i.tablespace_name, i.pct_freeFROM dba_indexes i, dba_ind_columns cWHERE i.table_name = c.table_nameAND i.index_name = c.index_nameAND i.owner = c.index_ownerAND i.owner = 'HR'AND (i.owner, i.index_name) NOT IN(SELECT index_owner, index_nameFROM dba_constraintsWHERE owner = 'HR'AND index_name IS NOT NULL)ORDER BY i.table_name, i.index_name, c.column_positionThe output obtained has been <strong>for</strong>matted as follows:TABLE_NAME INDEX_NAMECOLUMN_NAMEUNIQUENESSTABLESPACE_NAMEPCT_FREEDEPARTMENTSDEPT_LOCATION_IX LOCATION_ID NONUNIQUEINDX 10EMPLOYEES EMP_DEPARTMENT_IXINDX 10EMPLOYEES EMP-JOB-IXINDX 10DEPARTMENT_IDJOB_IDNONUNIQUENONUNIQUE

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 139EMPLOYEES EMP_MANAGER_IX MANAGER_ID NONUNIQUEINDX 10EMPLOYEES EMP_NAME_IX LAST_NAME NONUNIQUEINDX 10EMPLOYEES EMP_NAME_IXFIRST_NAMENONUNIQUEINDX10JOB_HISTORYJHIST_ DEPARTMENT_IX DEPARTMENT_ID NONUNIQUEINDX10JOB_HISTORYJHIST_EMPLOYEE_IX EMPLOYEE_ID NONUNIQUEINDX10JOB_HISTORYJHIST_ JOB_IX JOB_ID NONUNIQUEINDX10LOCATIONS LOC_CITY_IX CITY NONUNIQUEINDX10LOCATIONS LOC_COUNTRY_IX COUNTRY_ID NONUNIQUEINDX10LOCATIONS LOC_STATE_PROVINCE_IX STATE_PROVINCE NONUNIQUEINDX10This in<strong>for</strong>mation can be used to create indexes in SQL Server as follows:CREATE NONCLUSTEREDINDEX hr.dept_location_ixON hr.departments(location_id)WITH FILLFACTOR = 90ON HR_INDXCREATE NONCLUSTERED INDEX hr.emp_name_ixON hr.employees(last_name, first_name)WITH FILLFACTOR = 90ON HR_INDXBecause indexes have been created over several steps, you should verify that anequivalent index has been created in SQL Server <strong>for</strong> each index in <strong>Oracle</strong>.In <strong>Oracle</strong>, generate a listing of all indexes using the following command:8.SELECT i.table_name, i.index_name,c.column_name, i.uniqueness, i. tablespace_name,i.pct_freeFROM dba_indexes i, dba_ind_columns cWHERE i.table_name = c.table_nameAND i.index_name = c.index_nameAND i.owner = c.index_ownerAND i.owner = 'HR'ORDER BY i.table_name, i.index_name, c.column_positionIn SQL Server, execute the following command on each table with the table namesubstituted <strong>for</strong> name to retrieve in<strong>for</strong>mation on the indexes available <strong>for</strong> the table:sp_helpindex [ @objname = ] 'name'Create views.Extract the views and their definition from <strong>Oracle</strong> using the following command:SELECT view_name, textFROM dba_viewsWHERE owner = 'HR'The output provides the view query.

140 Developing: Databases — <strong>Migrating</strong> SchemasThe query <strong>for</strong> DEPT is as follows:select "DEPARTMENT_ID", "DEPARTMENT_NAME", "MANAGER_ID", "LOCATION_D","DEPT_LOC"from hr.departmentsThe query <strong>for</strong> EMB_DETAILS_VIEW is as follows:SELECTe.employee_id,e.job_id,e.manager_id,e.department_ id,d.location_id,l.country_id,e.first_name,e.last_name,e.salary,e.commission_pct,d.department_ name,j.job_title,l.city,l.state_province,c.country_name,r.region_nameFROMemployees e,departments d,jobs j,locations l,countries c,regions rWHERE e.department_id = d.department_idAN D d.location_id = l.location_idAND l.country_id = c.country_idAN D c.region_id = r.region_idAND j.job_id = e.job_idWITH READ ONLYFor the view DEPT, the view text shows capitalized names enclosed in doublequotes <strong>for</strong> the column names:select "DEPARTMENT_ID", "DEPARTMENT_NAME", "MANAGER_ID", "LOCATION_D","DEPT_LOC" from hr.departmentsThis is an indication that the column names were filled in by the system, and theoriginal DDL <strong>for</strong> the CREATE VIEW dept is as follows:select * from hr.departmentsAs pointed out in the discussion on using views instead of synonyms <strong>for</strong> tables,SQL Server retains the exact definition used in the DDL. <strong>Oracle</strong> does the samething when an asterisk (*) is not used. This behavior is shown in theEMP_DETAILS_VIEW view text. Thus, while converting the syntax, the DDL maybe changed back to an asteriskinstead of specifying every column.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 141Note The DEPT view was added to the HR schema to demonstrate this point.The EMP_DETAILS_VIEW can be created under the HR schema using thefollowing command:CREATE VIEW hr.EMP_DETAILS_VIEW ASSELECTe.employee_id,e.job_id,e.manager_id,e.department_id,d.location_id,l.country_id,e. first_name,e.last_name,e.salary,e.commission_pct,d.department_name,j.job_title,l.city,l.state_province,c.country_name,r.region_nameFROM hr.employees e INNER JOIN hr.departments dON e.department_id = d.department_idINNER JOIN hr.locations lON d.location_id = l.location_idINNER JOIN hr.countries cON l.country_id = c.country_idINNER JOIN hr.regions rON c.region_id = r.region_idINNER JOIN hr.jobs jON j.job_id = e.job_id;The WITH READ ONLY clause will have to be en<strong>for</strong>ced by ensuring only SELECTprivilege is given to users.9. Create functions, stored procedures, and packages.The following command can be used to get a listing of all functions defined by theschema owner, HR:SELECT object_name, object_typeFROM dba_objectsWHERE owner = 'HR'AND object_type IN ('FUNCTION', 'PROCEDURE', 'PACKAGE', 'PACKAGE BODY')The output retuned is:OBJECT_NAME OBJECT_TYPEADD_JOB_HISTORY PROCEDURESECURE_DML PROCEDUREThe source code of each of these objects can be extracted from the data dictionaryusing the command:

142 Developing: Databases — <strong>Migrating</strong> SchemasSELECT textFROM dba_sourceWHERE owner = 'HR'AND NAME = 'ADD_JOB_HISTORY'ORDER BY lineThe output is:TEXTPROCEDURE add_job_history( p_emp_id job_history.employee_id%type, p_start_date job_history.start_date%type, p_end_date job_history.end_date%type, p_job_id job_history.job_id%type, p_department_id job_history.department_id%type)ISBEGININSERT INTO job_history (employee_id, start_date,end_date, job_id, department_id)VALUES(p_emp_id, p_start_date, p_end_date, p_job_id, p_department_id);END add_job_history;An overview of the ef<strong>for</strong>t in migrating functions, stored procedures, and packageshas been given in the "Stored Programs" section of this chapter. For a detaileddiscussion of migrating the code, refer to the "<strong>Migrating</strong> the Data Access" sectionin Chapter 11.10. Create synonyms.Synonyms are used with non-schema users to provide location transparency.Because SQL Server does not support synonyms, the SQL will have to bemodified to contain a schema prefix.Note An <strong>Oracle</strong> schema could potentially have objects or properties that are not inuse. Examples of such objects are disabled constraints, invalid views, invalidsynonyms, invalid function, invalid procedures, and dropped column (not purgedfrom table). Although it is not necessary to migrate these objects to the newenvironment, certain clients may differ in this regard.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 1437Developing: Databases —<strong>Migrating</strong> the Database UsersIntroduction and GoalsChapter 6, "Developing: Database — <strong>Migrating</strong> Schemas," concentrated strictly on themigration of the schema, its owner, and objects. The other class of database users is theone that accesses the data in the tables of these schemas. These users do not own anyobjects, such as tables or views, but may have some synonyms that may point to thetables and views in the application schema. The ef<strong>for</strong>t in migrating these users toMicrosoft® SQL Server is in creating the users and reproducing the privileges theypossess in the <strong>Oracle</strong> database. The privileges may be granted to the user directly orthrough roles. The migration of roles is also discussed in this chapter.The steps in migrating the users are:1. Create the user account.2. Create roles and grant privileges.Create User AccountsA detailed discussion of database accounts, authentication, and password managementwas provided in the "Create the Schema Owner" section of Chapter 6. The creation ofuser accounts does not differ from the creation of schema accounts in any respect. Thedifference is in the privileges that they are granted. Figure 7.1 shows the relationshipbetween database users, roles, and schema objects.

144 Developing: Databases — <strong>Migrating</strong> the Database UsersFigure 7.1Dependencies in the migration of users from <strong>Oracle</strong> to SQL ServerThe following query can be run in the source <strong>Oracle</strong> database to create a list of users thathave privileges on any object in a specific schema. The query has been constrained toonly a specific schema and its users. This aids in situations where only a subset of theschemas and the related users are migrated from an <strong>Oracle</strong> database.SELECT granteeFROM dba_tab_privsWHERE owner = usernameUNIONSELECT granteeFROM dba_col_privsWHERE owner = usernameThe grantee could be a user or a role. As with the case of the schema owner, thefollowing query can be used to retrieve the characteristics of any login.SELECT du.username,DECODE(du.password,'EXTERNAL','EXTERNAL','DB') "AUTHENTICATION MODE",du.default_tablespace, du.temporary_tablespace,dp.resource_name, dp.limitFROM dba_users du, dba_profiles dpWHERE du.profile = dp.profileAND dp.resource_type = 'PASSWORD'AND du.username = usernameThe system stored procedure sp_grantlogin is used to create a SQL Server login <strong>for</strong> adomain-authenticated account, and sp_addlogin is used to create a SQL Serverauthenticated account. The procedure sp_grantdbaccess is used to create user

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 145accounts in the individual databases <strong>for</strong> these logins. User accounts should be created ina database only if there are objects in the database the user needs to access.Note While migrating <strong>Oracle</strong> accounts, there may be user accounts that are locked.The <strong>Oracle</strong> DBA of the original environment should be consulted be<strong>for</strong>e makingdecisions on whether to migrate these accounts.Create Roles and Grant PrivilegesA privilege is permission (as it is called in SQL Server) to per<strong>for</strong>m work inside thedatabase. <strong>Oracle</strong> and SQL Server provide two sets of privileges: system privileges andobject privileges.Table 7.1 provides terms relating to privileges in <strong>Oracle</strong> and SQL Server that can helpavoid any confusion during a migration.Table 7.1: Privilege Terms Used in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong> TerminologyPrivilegeSystem privilegeObject privilegePredefined role permission (<strong>for</strong> example,DBA)GranteeSQL Server TerminologyPermissionStatement permissionObject permissionImplied permissions (<strong>for</strong> example,sysadmin)Security accountWhile <strong>Oracle</strong> has several object privileges, the ones commonly granted to users areSELECT, INSERT, DELETE, and UPDATE on tables and EXECUTE on storedprograms. SQL Server has the same object privileges.System and object privileges can be granted to users either directly or through roles.SQL Server also offers the WITH GRANT OPTION clause <strong>for</strong> object privileges.<strong>Oracle</strong> and SQL Server differ a lot in the system privileges that are available. <strong>Oracle</strong> hasvery granular (more than 100) system privileges. SQL Server system privileges, calledstatement permissions, are restricted to the following list:● BACKUP DATABASE● BACKUP LOG● CREATE DATABASE● CREATE DEFAULT● CREATE FUNCTION● CREATE PROCEDURE● CREATE RULE● CREATE TABLE● CREATE VIEWThe rest of the <strong>Oracle</strong> system privileges are bundled into several large fixed roles. Forexample, the fixed database role db_datareader is equivalent to the SELECT ANYTABLE system privilege in <strong>Oracle</strong>.<strong>Oracle</strong> and SQL Server offer predefined roles and user-defined roles. The predefinedroles have powerful system and object privileges on the data dictionary and the instance.

146 Developing: Databases — <strong>Migrating</strong> the Database UsersThe "Roles" topic in SQL Server Books Online provides a list of fixed server roles andfixed database roles and their description. User-defined roles can be granted system aswell as object privileges.The privileges <strong>for</strong> administrative users should be revisited when migrating to aSQL Server database because each database is far more self-contained with respect toadministration. Fixed database roles can be granted privileges on a single databaseinstead of the system-wide powers af<strong>for</strong>ded by the DBA role in <strong>Oracle</strong>. A completediscussion of the system privileges and their equivalents in SQL Server is beyond thescope of this guidance. For more in<strong>for</strong>mation about the fixed server roles and fixeddatabase roles available in SQL Server and their descriptions, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/architec/8_ar_da_3xns.asp.There are two important stored procedures <strong>for</strong> granting system privileges in SQL Server:sp_addsrvrolemember can be used <strong>for</strong> granting fixed system roles andsp_addrolemember can be used <strong>for</strong> granting fixed database roles.In <strong>Oracle</strong>, roles are available at the instance or server level and can be granted privilegeson more than one schema. SQL Server user-defined roles are local to a database andowned by a user. Hence, when migrating a role from <strong>Oracle</strong> to SQL Server, a role has tobe created in each of the databases in which privileges have to be granted. To grant privileges and roles to a user, follow these steps:1. Create role(s) in each of the SQL Server database(s) that will be used to controlthe permission given to users. A role can be created in a database using thefollowing commands:Use databaseGOsp_addrole [ @rolename = ] 'role_name'[ , [ @ownername = ] 'owner' ]GOWhere role_name is the name of the role to be created and owner is the user whowill own the role (which will normally be the schema owner or a security account<strong>for</strong> the application).2. System level privileges can either be granted to the role created in step 1 ordirectly to the user. The following statement can be used <strong>for</strong> granting systemprivileges to roles and users:GRANT {ALL | system_privilege_name}TO {user_name | role_name}Where system_privilege_name is the system privilege to be granted, user_name isthe name of the user to whom the grant is made, and role_name is the name of therole through which the privileges will be granted to the user.3. As with system privileges, object privileges can be granted directly to the user orthrough roles. The following statement can be used to grant object privileges tousers and roles:GRANT {ALL | object_privilege_name}ON object_nameTO {user_name | role_name}[WITH GRANT OPTION]Where object_privilege_name is the object privilege to be granted, object_name isthe object on which the privilege is granted, user_name is the name of the user towhom the grant is made, and role_name is the name of the role through which theprivileges will be granted to the user.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 147Object privileges can also be granted at the more granular column level instead ofon the entire table. The following statement can be used to grant privileges on oneor more columns of a table:GRANT {ALL | object_privilege_name}ON table_name ( column_name [,…] )TO {user_name | role_name}[WITH GRANT OPTION]Where object_privilege_name is the object privilege to be granted, table_name isthe table to which the column belongs, column_name is the specific column on whichthe privilege is being granted, user_name is the name of the user to whom the grantis made, and role_name is the name of the role through which the privileges will begranted to the user.4. If privileges are being granted through a role, the role can be granted to a userusing the following command:sp_addrolemember [ @rolename = ] 'role_name' ,[ @membername = ] 'user_name'Where role_name is the name of the role to be granted and user_name is the targetuser.Sample User MigrationWhen a user is migrated from <strong>Oracle</strong> to SQL Server, the same security architecture canbe maintained by creating roles and granting privileges in a functionally equivalentmanner. The difference in the implementation is depicted in Figure 7.1.Privileges on objects in a database are given to a local user account at the databaselevel and do not transgress database boundaries. This implies that, <strong>for</strong> a server orinstance level login, a user account has to be created in each of the databases that itneeds privileges in (either directly or through roles). The following steps are a practicalexample of how to migrate the security architecture of an application and its user from<strong>Oracle</strong> to SQL Server. This example is an extenuation of the migration of the HR schemain <strong>Oracle</strong> which was started in Chapter 6.1. Create the user account in SQL Server <strong>for</strong> each of the <strong>Oracle</strong> users.In <strong>Oracle</strong>, there is a single user account that is granted privileges on variousschemas. In SQL Server, the single user account translates to a two-tierimplementation.a. Obtain a list of user accounts in the <strong>Oracle</strong> database that have to be migratedto SQL Server. The list can be obtained using the following statement:SELECT granteeFROM dba_tab_privsWHERE owner = 'HR'UNIONSELECT granteeFROM dba_col_privsWHERE owner = 'HR'where owner is the name of the schema whose security is being migrated.The following is the output <strong>for</strong> the HR schema.GRANTEEOE

148 Developing: Databases — <strong>Migrating</strong> the Database Usersb.Obtain the characteristics of user accounts in <strong>Oracle</strong> that were identified insubstep a.The following statement can be executed to gather in<strong>for</strong>mation on each of theuse rs to be migrated:SELECT du.username,DECODE(du.password,'EXTERNAL','EXTERNAL','DB')"AUTHENTICATION MODE",du.default_tablespace, du.temporary_tablespace,dp.resource_name, dp.limitFROM dba_users du, dba_profiles dpWHERE du.profile = dp.profileAND dp.resource_type = 'PASSWORD'AND du.username = 'OE'where OE is the name of the user that is being migrated.The privileges granted to OE user are:USERNAME AUTHENTICATION MODE DEFAULT_TABLESPACETEMPORARY_TABLESPACE RESOURCE_NAMELIMITOEDBEXAMPLETEMPFAILED_LOGIN_ATTEMPTS UNLIMITEDOEDBEXAMPLETEMPPASSWORD_LIFE_TIME UNLIMITEDOEDBEXAMPLETEMPPASSWORD_REUSE_TIME UNLIMITEDOEDBEXAMPLETEMPPASSWORD_REUSE_MAX UNLIMITEDOEDBEXAMPLETEMPPASSWORD_VERIFY_FUNCTION NULLOEDBEXAMPLETEMP PASSWORD_LOCK_TIME UNLIMITEDOE DB EXAMPLETEMP PASSWORD_GRACE_TIME UNLIMITEDc.Create SQL Server login accounts that provide access to the SQL Serverinstance.Because the <strong>Oracle</strong> account in this example is database-authenticated andnone of the password features are in use, the SQL Server login can be createdas a SQL Server-authenticated login.The following commands can be executed to create the SQL Server login <strong>for</strong>the user OE with the password OE in the HRDATA database into which the HRschema's objects are migrated:Use MASTEREXEC sp_addlogin@loginame='OE',@passwd='OE',@defdb='HRDATA'd. Create a user account in each of the databases in which the schema's objectshave been migrated.The databases in which user accounts have to be created depend on the<strong>Oracle</strong> schemas <strong>for</strong> which the user has privileges and the SQL Server

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 149database to which they have been migrated. The following statement can beused to see the schemas on which the user OE has been granted privileges.SELECT ownerFROM dba_tab_privsWHERE grantee = 'OE'UNIONSELECT ownerFROM dba_col_privsWHERE grantee = 'OE'The output of the statement is as follows:OWNERHRSYSIn Chapter 6, the HR schema was migrated to the HRDATA database inSQL Server. SYS is the data dictionary owner, which translates to masterdatabase in SQL Server. However, because the data dictionary is dividedbetween the master database and the application (user-created) databases,<strong>for</strong> an application user, an account in the master database may not benecessary and should be created after proper scrutiny of the securityrequirements.The following commands can be used to create a user <strong>for</strong> the OE login in theHRDATA database:Use HRDATAEXEC sp_grantdbaccess@loginame='OE',@name_in_db='OE'2.Create roles through which the privileges will be granted to users.Only those roles that are granted to users and schemas that are being migratedwill be created in SQL Server. Also, the role has to be created in each of thedatabases with the application schema as the owner.The following statement can be used to retrieve the roles that have been grantedto the user OE:SELECT granted_role, admin_optionFROM dba_role_privsWHERE grantee = 'OE'The following is the output <strong>for</strong> the OE user:3.GRANTED_ROLECONNECTRESOURCEADMIN_OPTIONNONOThe CONNECT and RESOURCE roles are both system roles. No application rolesare in use <strong>for</strong> this schema. Hence all system and object privileges will be granteddirectly to the user. If you want to introduce roles in SQL Server, it should beper<strong>for</strong>med at this point.Grant privileges and/or roles to the user.The roles that were identified in Step 2 are granted here.The CONNECT role gives the user the capability to connect to the <strong>Oracle</strong>database. In SQL Server, the same privileges are inherently granted when thelogin and user accounts are created. The RESOURCE role gives the capability tocreate objects in the database. Thereis no role in SQL Server that provides the

150 Developing: Databases — <strong>Migrating</strong> the Database Userssame level of privileges as RESOURCE. As a result, the following privileges aregranted.GRANT CREATE FUNCTION TO OEGRANT CREATE PROCEDURE TO OEGRANT CREATE TABLE TO OEGRANT CREATE VIEW TO OEThe following statement is used to retrievethe OE user:system and object privileges granted toSELECT do.object_type Lvl, dtp.privilege, dtp.grantable, dtp.owner,dtp.table_name, NULL column_nameFROM dba_tab_privs dtp, dba_objects doWHERE dtp.owner = do.ownerAND dtp.table_name = do.object_nameAND grantee = 'OE'UNIONSELECT 'Column', privilege, grantable, owner, table_name, column_nameFROM dba_col_privsWHERE grantee = 'OE'UNIONSELECT 'Sys Priv', privilege, admin_option, NULL, NULL, NULLFROM dba_sys_privsWHERE grantee = 'OE'ORDER BY privilege, grantable,owner, table name, column nameThe following output is returned <strong>for</strong> the OE user:LVL PRIVILEGE GRANTABLEOWNER TABLE_NAME COLUMN_NAMESys Priv CREATE SNAPSHOT NOSys Priv QUERY REWRITENOSys Priv UNLIMITED TABLESPACENOTable EXECUTE NO SYS DBMS_STATSTable REFERENCES NO HR COUNTRIESTable REFERENCES NO HR EMPLOYEESTable REFERENCES NO HR LOCATIONSTable SELECT NO HR COUNTRIESTable SELECT NO HR DEPARTMENTSTable SELECT NO HR EMPLOYEESTable SELECT NOHR JOBSTable SELECT NOHR JOB_HISTORYTable SELECT NOHR LOCATIONSBased on the preceding output, grant statements can be devised as follows:GRANT SELECT ON countries to OE;GRANT SELECT ON departments to OE;GRANT SELECT ON employees to OE;GRANT SELECT ON jobs to OE;GRANT SELECT ON job_history to OE;GRANT SELECT ON locations to OE;SQL Server does not contain equivalents <strong>for</strong> CREATE SNAPSHOT, QUERYREWRITE, REFERENCES, and UNLIMITED TABLESPACE privileges.The CREATE SNAPSHOT privilege is related to replication, and the QUERYREWRITE privilege is relatedto data warehousing, and both are beyond the scope

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 151of this guide. The REFERENCES privilege is <strong>for</strong> creating <strong>for</strong>eign key constraintsacross schemas which are not allowed in SQL Server. SQL Server does notimpose storage quotas on schemas; an equivalent <strong>for</strong> REFERENCES is notneeded in SQL Server.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 1538Developing: Databases —<strong>Migrating</strong> the DataIntroduction and GoalsMigration of the data represents the final task in the migration of an <strong>Oracle</strong> database toMicrosoft® SQL Server. Even though SQL Server offers several tools that make thebulk transfer of data from an external source easier, aspects of the migration that cannotbe automated, such as planning the migration and validating that the data has beenmoved completely and without error, should be prioritized.The data migration task can be broken up into the following three subtasks:1. Planning. It is important to understand the migration options, evaluate thecharacteristics of the source data, and evaluate environmental and businessconstraints.2. Execution. This subtask involves preparing the database and transferring thedata.3. Validation. This subtask accounts <strong>for</strong> all the data and verifies data integrity.Planning the Data MigrationThere are two planning prerequisites. Be<strong>for</strong>e making any decisions, you should first fullyunderstand the various options available <strong>for</strong> transferring the data from an <strong>Oracle</strong>database to a SQL Server database, particularly the advantages and limitations of eachof the options. The second prerequisite is to document all the factors or characteristics ofthe original environment that could influence your decision making from the availableoptions. These prerequisites are discussed in detail under the following headings.Options <strong>for</strong> MigrationIn an <strong>Oracle</strong> to SQL Server migration scenario, the two avenues <strong>for</strong> migrating data are toeither push the data from <strong>Oracle</strong> to SQL Server, or to pull the data from <strong>Oracle</strong> intoSQL Server.Even though <strong>Oracle</strong> can communicate with heterogeneous databases, the operation isonly at a transactional level and cannot be taken advantage of <strong>for</strong> bulk data operations asneeded in a migration situation. The only specialized utility <strong>Oracle</strong> provides <strong>for</strong> exportingdata out of the database is the export utility exp. This utility can only create dumps inbinary <strong>for</strong>mat that cannot be used <strong>for</strong> importing into a non-<strong>Oracle</strong> database.

154 Developing: Databases — <strong>Migrating</strong> the DataSQL Server is built <strong>for</strong> bulk copying of data, with specialized features and interfaces to alarg e host of data sources. Figure 8.1 shows the various paths that offer bulk copyfunctions <strong>for</strong> moving data from <strong>Oracle</strong>.Figure 8.1Paths <strong>for</strong> accessing an <strong>Oracle</strong> database from SQL ServerData can be migrated from <strong>Oracle</strong> to SQL Server using one of the following options:● Bulk Copy Program (bcp). bcp is a command line utility that uses the ODBC bulkcopy API in SQL Server. bcp cannot connect to an <strong>Oracle</strong> database and, whenemployed <strong>for</strong> moving data from <strong>Oracle</strong> to SQL Server, the data has to be an ASCIItext file. Multiple copies of bcp can be run in parallel while working on the sametarget table. The number of parallel sessions is limited by the number of CPUs onthe server.For in<strong>for</strong>mation about using the bcp utility with Microsoft SQL Server, refer to the"bcp Utility" article available athttp://msdn.microsoft.com/library/default.asp? url=/library/enus/coprompt/cp_bcp_61et.asp.● BULK INSERT. BULK INSERT is a T-SQL statement. This statement has thesame kind of functionality as bcp and can be used to import <strong>Oracle</strong> data that hasbeen captured in a text file. This operation scales linearly with the number ofCPUs, but it is limited to one thread per CPU.For in<strong>for</strong>mation on the complete BULK INSERT T-SQL statement and its usage,refer to http://msdn.microsoft.com/library/default.asp?url=/library/enus/tsqlref/ts_ba-bz_4fec.asp.● Data Trans<strong>for</strong>mation Service (DTS). DTS is a powerful set of GUI tools that canbe used to extract, trans<strong>for</strong>m, and populate SQL Server databases from <strong>Oracle</strong>

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 155E ven though the functionality to trans<strong>for</strong>m data during the migration exists, anassumption made during this discussion is that no trans<strong>for</strong>mation of the source data isrequired. The BULK INSERT T-SQL statement has been documented in SQL ServerBooks Online as the fastest bulk copy method because it executes with the SQL Serverprocess. In contrast, bcp and DTS are external utilities that are running as their ownprocesses. As a result, they have the overhead of having to communicate withS QL Server (using IPC) and pass it data from the source. When bcp and DTS are run ona client computer, there is network overhead as well.bcp is faster than DTS when importing very large quantities of data into SQL Server, butit lacks some of the features of DTS. Studies have ranked bcp first in speed, followed byBULK INSERT, and then DTS. Refer to the SQL Server Magazine article "Showdown—bc p vs. DTS" available at http://www.winnetmag.com/Articles/Print.cfm?ArticleID =19760.Other factors must be considered in making a migration strategy decision. These factorsare discussed under the following heading.The Microsoft SQL Server Migration Assistant (SSMA) provides the Schema and DataMig rator tool, which can migrate the schema and also move the data. The data ismigrated using the SQL Server Linked Server feature to connect directly to <strong>Oracle</strong>through the <strong>Oracle</strong> Gateway. For more in<strong>for</strong>mation on the Schema and Data Migrator andto download the tool refer to http://www.microsoft.com/sq l/migration. The beta version ofthis tool is available as of the date of publishing this solution. Version 1.0 of the tool isslated to be available in June 2005.Factors in Migrationdatabases. DTS wizards make the entire process of defining and per<strong>for</strong>ming theimport very easy. DTS provides access to the BULK INSERT statement in the DTSBulk Insert task. In addition to working with text files, DTS can use OLE DB andODBC providers to connect to an <strong>Oracle</strong> database. The direct connectivity to<strong>Oracle</strong> provides the capability to work with binary large objects (BLOBs).For an overview of DTS, refer tohttp://msdn.microsoft.com/SQL/sqlwarehouse/DTS/default.aspx?pull=/library/en-us/dnsql2k/html/dts_overview.asp.Given the various options <strong>for</strong> migrating data from <strong>Oracle</strong> to SQL Server, the choice isinfluenced by several business and environment factors. Some of the important factors(the more critical ones stated first) are:● Volume of data. The amount of data that has to be migrated is the number onefactor. High volumes of data require more storage, more processing power, largernetwork bandwidth, larger migration window, and increased risk of failure.For more in<strong>for</strong>mation on how to optimize large data imports in SQL Server, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/optimsql/odp_tun_1a_5gyt.asp.● Migration window. The time window available <strong>for</strong> migration may necessitatemultiple parallel sessions, more resources, and staging of data.● Type of data. The existence of BLOBs can be handled only by DTS.● Server processing capacity. Running bcp on the same server as the databasereduces network overhead of bcp talking to SQL Server, but it consumes CPU onthe server.● Storage availability. The amount of storage available in both the source andtarget environment influences the choice of migration method and strategy. Forexample, moving the text files on to the target server reduces network overhead.

156 Developing: Databases — <strong>Migrating</strong> the Data●●●●The configuration of storage also affects the speed of migration, such as puttingthe source text file and the database files on separate disks or devices.Data source. The capability to create flat files in the source environment affectsthe choice of migration method. A fixed-field <strong>for</strong>mat source file takes a lot morestorage and is considerably slower. Delimited <strong>for</strong>mat is recommended.Type of database. Batch, OLTP, or DSS database type defines the type ofschema objects and their characteristics.Recovery Model. Database recovery models should be set to simple or bulk-Use proven methods. Only use methods and options that have proven to work bylogged to minimize logging of BULK INSERT. The capability to do so can beaffected if there are databases being shared by other applications that are in useduring the migration.the industry and <strong>for</strong> the environment. For example, OLE DB has been proven to befaster than ODBC while providing all of the same features.Migration StrategyThe following are some of the factors that can contribute to the creation of a robustmigration strategy:● Minimize logging. The actions that should be taken to minimize logging are:● Set the database recovery model to bulk-logged or simple.● Use TABLOCK hint during bulk loading.● The target table should either be empty or no indexes should be defined on it.● Disable or drop all triggers on the target table.● Drop replication on the target table.●●●●●●●Reduce operations overhead. You should drop indexes, constraints, defaults,and identity operations. When a clustered index is planned <strong>for</strong> a table, order thedata while creating the output file from <strong>Oracle</strong>. The BULK INSERT statementaccepts the ORDER clause and the bcp utility accepts the ORDER hint to specifythe sort of the data files. Avoid concurrent access by other users to the tablesbeing loaded. The TABLOCK hint can be used while per<strong>for</strong>ming BULK INSERT orbcp.Improve parallelism. With a large amount of data (which is the assumption madethroughout this section), the best per<strong>for</strong>mance can only be achieved by per<strong>for</strong>mingloads in parallel. The parallelism can be inter-table or intra-table.Avoid side effects. Turn off triggers, bypass identity, bypass default columnsetting, and drop replication.Reduce complexity. When the source database has a large number of tables,break it down into logical subsets and stage data, if necessary. Importing static andhistorical data can be per<strong>for</strong>med in advance.Reduce risk. Break down larger source data text files using either an editor or byspecifying ranges in the SQL queries that are used <strong>for</strong> exporting the data into spoolfiles. Any failures that occur when dealing with large files waste time andresources. In a migration containing very volatile data, the migration should becompleted in a single stage instead of multiple stages.Commit more resources. Additional CPU, memory, and storage should beacquired <strong>for</strong> the migration.Auditing. Include audit steps during the process. This enables trapping of errorsas they occurduring the transfer of data.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 157Table 8.1 details the suitable method of data porting <strong>for</strong> different migration environments.Table 8.1: Data Migration OptionsScenarioData migration environments that have high per<strong>for</strong>mancereq uirements and have huge volumes of data to betransferredMethods of data migration that use a small amount of scripts bcpApplications that need to use scripts on the data transferprocessAp plications that require high-powered trans<strong>for</strong>mation ofmoderate volumes of dataTab les contain large objects (LOB) such as RAW, LONG,BLOB, and CLOBRecommended methodbcp or BULK INSERTBULK INSERTHere are some additional considerations <strong>for</strong> planning the migration:● The final strategy should be based on the amount of time available <strong>for</strong> the actualdeployment and cutover.● The per<strong>for</strong>mance of the load operation should be dependent on the chosenstrategy.● Instead of sticking to a single method, a combination of methods can be employedbased on the strengths and weaknesses of the individual methods. For example,DTS need not be used as the migration method just because there are LOBcolumns.● The tables in the migration can be broken up and a combination of methods couldbe used, taking advantage of the strengths of each.● Parallel operation should be applied on large tables.● The per<strong>for</strong>mance of bcp versus BULK INSERT has been found to vary. Test boththese approaches in your scenario be<strong>for</strong>e making a decision.● Test data files should be created and the per<strong>for</strong>mance of the various methodsmeasured in the target environment.● A prototype of the final strategy should be created and the process should bepracticed and perfected be<strong>for</strong>e deployment.DTSDTSExecuting the Data MigrationThis section details the steps to be per<strong>for</strong>med <strong>for</strong> migrating data. The section has beenbroken into three tasks:1. Pre-implementation2. Implementation3. Post-implementationEach of these tasks is discussed in detail under the following headings.

158 Developing: Databases — <strong>Migrating</strong> the DataPre-Implementation TasksThe following tasks have to be completed be<strong>for</strong>e per<strong>for</strong>ming the migration:1. Back up the database.Delete any test data from the target database and create a full backup of the emptydatabase. Restoring the backup will be faster than the work involved in rolling backa failed or incomplete migration.2.Export <strong>Oracle</strong> data into text files.Data from each table that has to be migrated is exported into comma-delimitedASCII text files.Note The string data should be optionally enclosed in double quotation marks (")in case there are commas in the column data. The date fields can be exported inthe desired <strong>for</strong>mat using the TO_CHAR function.Sample:In SQL*Plus, connect to the schema and execute the following command:desc countriesThe output is:Name Null? Type----------------------------------------- -------- -----------------COUNTRY_IDCOUNTRY_NAMEREGION_IDNOT NULL CHAR(2)VARCHAR2(40)NUMBERCreate a .sql file (example countries.sql) with the following content:set pages 0set lines 10000set trimspool onset feedback offspool /data/dump/countries.csvselect country_id||','||country_name||','||region_idfrom countries;spool offExecuting this file using SQL*Plus produces the following text file that can beimported into SQL Server.Note If these commands are typed at the command prompt inside the SQL*Plusutility in Microsoft Windows®, the output file will contain extraneous promptcommands at the beginning and end of the file. This does not occur if thecommands are executed from a file.AR,Argentina,2AU,Australia,3BE,Belgium,1BR,Brazil,2CA,Canada,2CH,Switzerland,1CN,China,3DE,Germany,1

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 159DK,Denmark,1EG,Egypt,4FR,France,1HK,HongKong,3IL,Israel,4IN,India,3IT,Italy,1JP,Japan,3KW,Kuwait,4MX,Mexico,2NG,Nigeria,4NL,Netherlands,1SG,Singapore,3UK,United Kingdom,1US,United States of America,2ZM,Zambia,4ZW,Zimbabwe,4Note Using SQL*Plus and the spool command is the best way to create commaseparated(CSV) exports of <strong>Oracle</strong> table data. Other solutions available based onthe functionality currently available in <strong>Oracle</strong> are DBMS_OUTPUT, UTL_FILE, andPro*C. For details on the various methods, refer tohttp://asktom.oracle.com/~tkyte/flat/index.htmlHowever, these options should be employed only if the data is being manipulatedduring the output process because there are per<strong>for</strong>mance overheads in their use.3. Set the recovery model of the SQL Server database.Change the recovery model of the target SQL Server database to bulk-logged orsimple. Bulk-logged mode is preferred.The following command sets the recovery model of a database to bulk-logged:ALTER DATABASE database_nameSET RECOVERY BULK_LOGGEDwhere database_name is the name of the database whose recovery model has to beset.4. Disable all constraints.Identify and disable all constraints, including CHECK, PRIMARY KEY, FOREIGNKEY, and UNIQUE. Create scripts to restore them.In SQL Server, only FOREIGN KEY and CHECK constraints can be disabled.The following command can be used to disable FOREIGN KEY and CHECKconstraints of a SQL Server table:ALTER TABLE table_name NOCHECK CONSTRAINT ALLwhere table_name is the name of the table whose constraints have to be disabled.PRIMARY KEY and UNIQUE constraints have to be dropped.The following command can be used to drop PRIMARY and UNIQUE by specifyingtheir name:ALTER TABLE table_name DROP CONSTRAINT constraint_namewhere constraint_name is the name of the constraint and table_name is the name ofthe table in which the constraint exists.

160 Developing: Databases — <strong>Migrating</strong> the DataNote By default, constraints are not checked when using bcp.5. Disable all triggers.Disable triggers on all tables into which data will be loaded.The following command can be used to disable all triggers on a table.ALTER TABLE table_name DISABLE TRIGGER ALLwhere table_name is the name of the table on which the triggers have to bedisabled.6. Drop all indexes.Drop all remaining indexes using the following command after saving the script torecreate them.DROP INDEXtable_name.index_namewhere index_name is the name of the index to be dropped and table_name is thetable on which the index exists.7. Handle IDENTITY column inserts.Let explicit values be copied into columns of a table with the Identity property.SET IDENTITY_INSERT table_name ONThis setting can be used only on a single table at a time. So ensure that this is setbe<strong>for</strong>e importing a table, or use the functionality in the method being used. In bcp,the same thing can be achieved using the -E switch. In BULK INSERT, use theKEEPIDENTITY argument.BULK INSERT 'table_name' FROM 'data file' WITH KEEPIDENTITY8. Back up the database.Create a full backup after the data migration be<strong>for</strong>e per<strong>for</strong>ming any validation ortesting.Implementation TasksThe implementation is the actual transfer of data from the source <strong>Oracle</strong> database to thetarget SQL Server database. The implementation can be per<strong>for</strong>med in one step or in twosteps. In the single step, implementation data is streamed directly from the <strong>Oracle</strong>database to the SQL Server database. In the two step process, data is extracted from the<strong>Oracle</strong> database into files and then loaded into the SQL Server database.S QL Server provides the following three to ols <strong>for</strong> loading data into a database:● The bulk copy program (bcp)● The BULK INSERT statement● Data Trans<strong>for</strong>mation Services (DTS)The use of these three tools in transferring data into SQL Server is discussed under thefollowing headings.Using bcpThe bcp utility can be accessed from the command prompt. The syntax <strong>for</strong> use isprovided here:bcp database_name.owner.table_name in data_file –t field_terminator –Sserver_name\instance_name–U username –P password –c –t ,

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 161where database_name.owner.table_name is the fully qualified name of the table into whichthe data is to be loaded, data_file is the name of the text file containing the data,field_terminator is the character that is used to delimit columns in a row,server_name\instance_name is the SQL Server instance, username is the login name, andpassword is the password <strong>for</strong> the user login.-c specifies that the data in the file is in the character data type-t specifies the field terminatorFigure 8.2 shows the results of executing this command at the Windows commandprompt.Figure 8.2Importing data from a text file using bcpTo make the bcp process repeatable, a <strong>for</strong>mat file should be created. The <strong>for</strong>mat file canbe created interactively by executing the b cp command, as shown in Figure 8.3.Figure 8.3Creating a <strong>for</strong>mat file <strong>for</strong> use with bcp imports

162 Developing: Databases — <strong>Migrating</strong> the DataThe <strong>for</strong>mat file looks like this:8.031 SQLCHAR 0 2 "," 1 COUNTRY_ID SQL_Latin1_General_CP1_CI_AS2 SQ LCHAR 0 40 "," 2 COUNTRY_NAME SQL_Latin1_General_CP1_CI_AS3 SQLNUMERIC 0 19 "\r\n" 3 REGION_ID ""Refer to the topic "Using Format Files" in SQL Server Books Online <strong>for</strong> more in<strong>for</strong>mationabout <strong>for</strong>mat files.Note The <strong>for</strong>mat file will have to be modified to handle text files that contain columndata values and which are enclosed by quotation marks (").The <strong>for</strong>mat file can be used <strong>for</strong> future imports into the same table by using the -f switch.This is illustrated in Figure 8.4. In the example, the <strong>for</strong>mat file is assumed to have beencopied to C:.Figure 8.4Importing data from a text file using bcp <strong>for</strong>mat fileTable 8.2 contains the additional arguments that are relevant while importing largevolumes of data from <strong>Oracle</strong>.Table 8.2: Additional Arguments of the bcp UtilityArgument (or option)Description-k bypasses DEFAULT definition-h "hints" bulk copy hints-E allows Identity insert-a network packets size 512 to 65536 (default4096)-e error_file logs errors during the import-b batch_size uses default, which is all rows in the fileNote Hidden characters in text files can cause problems such as the "unexpected nullfound" error. Care has to be taken when opening and manipulating text files containingdata.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 163Using BULK INSERTThe BULK INSERT T-SQL statement provides the same functionality as the bcp utility.The major difference is that this functionality is from within a database session.The following statement achieves the same work as was demonstrated with bcp:BULK INSERT hrdata.hr.countries FROM 'c:\countries.csv'WITH (DATAFILETYPE = 'char',FIELDTERMINATOR = ',',ROWTERMINATOR = '\n')Note Only members of the sysadmin role can use BULK INSERT.Table 8.3 contains additional arguments that need to be used while importing largeamounts of <strong>Oracle</strong> data.Table 8.3: Additional Arguments Available with the BULK INSERT CommandArgument (or option)Description-k bypasses DEFAULT definitionTABLOCKlocksKEEPIDENTITYallows values to be specified <strong>for</strong> identitycolumnFIRE_TRIGGERS trigger execution is not suppressedCHECK_CONSTRAINTSconstraints on table have to be checkedBATCHSIZEuse default, which is all rows in the fileNote For more in<strong>for</strong>mation about the bulk copy operations and on improving itsper<strong>for</strong>mance, refer to "Optimizing Bulk Copy Per<strong>for</strong>mance" athttp://msdn.microsoft.com/library/en-us/optimsql/od p_tun_1a_5gyt.asp?frame=true,and "Bulk Copy Per<strong>for</strong>mance Considerations" at http://msdn.microsoft.com/library/en-us/adminsql/ad_impt_bcp_5zqd.asp.For in<strong>for</strong>mation on different switches available with Bulk Insert, refer tohttp ://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_ba-bz_4fec.asp.Using DTSThis section is used to demonstrate how DTS wizards can be used to import data intoSQL Server tables from text files and directly from an <strong>Oracle</strong> database. The DTS Import/Export Wizard can be launched from Enterprise Managerusing the following steps or using the DTS Import Wizard:1. Expand Server.2. Right-click Databases, click All Tasks, and then click Import Data.3. Click the Next button on the wizard's Welcome screen.4. The next window presented is <strong>for</strong> choosing the data source. In the DataSource drop-down list choose Text File. Pick the file containing <strong>Oracle</strong> tabledata in the File name text box.

164 Developing: Databases — <strong>Migrating</strong> the Data5. The file <strong>for</strong>mat characteristics are chosen in the next window. The file typeshould be ANSI, and the row delimiter should be {CR}{LF}. If column datavalues are quoted, it can be specified in the Text qualifier field. The delimitercharacter, which is a comma (,), is specified in the next screen.6. The Microsoft OLE DB Provider <strong>for</strong> SQL Server should be chosen as thedestination and the server and login in<strong>for</strong>mation provided <strong>for</strong> the targetSQL Server instance.DTS offers the option of executing the import, saving it to a DTS package andscheduling. For in<strong>for</strong>mation on how to schedule DTS packages, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/dtssql/dts_pkgmng_4hm6.asp.DTS from <strong>Oracle</strong> DatabaseThe steps in creating a DTS package to connect and import data directly from the <strong>Oracle</strong>database is very similar to the process described in the previous section. Instead ofpointing the source to a file, an <strong>Oracle</strong> database is specified through an OLE DB orODBC provider <strong>for</strong> <strong>Oracle</strong>. The DTS Import/Export Wizard can be launched from Enterprise Managerusing the following steps or using the DTS Import Wizard:1. Expand Server.2. Right-click Databases, click All Tasks, and then click Import Data.3. Click the Next button on the wizard's Welcome screen.4. The next window presented is <strong>for</strong> choosing the data source. In the Data Sourcedrop-down list, choose the Microsoft ODBC Driver <strong>for</strong> <strong>Oracle</strong>. Enter the <strong>Oracle</strong>database alias and login in<strong>for</strong>mation.5. The Microsoft OLE DB Provider <strong>for</strong> SL Server should be chosen as the destinationand the server and login in<strong>for</strong>mation provided <strong>for</strong> the target SQL Server instance.6. The next screen offers the option of copying data from a table (or view) or using aquery.7. If the table or view option is chosen, the next screen provides a list of tables andviews available <strong>for</strong> import. The destination table name and trans<strong>for</strong>mationin<strong>for</strong>mation has to be provided along with the source table/view.8. If query option is chosen, the next screen provides a window <strong>for</strong> entering the querystatement. The destination table and trans<strong>for</strong>mation can be entered in the nextscreen.9. The execution of the import can be done immediately or scheduled <strong>for</strong> a later time.Note DTS has the capability of reading the table description from the <strong>Oracle</strong> databaseand creating tables in SQL Server. The wizard has been found to be faulty in its choiceof equivalent data types <strong>for</strong> SQL Server tables.Data can be migrated directly out of the database instead of through an intermediary fileif the interconnect between the servers hosting the two databases is very fast. Also, noadditional storage is required <strong>for</strong> the data files on the two servers. Use of files can reducethe deployment time if the data export can be done in advance and staged <strong>for</strong> import.For a case study on incrementally loading tables using the SQL Server bulk load options,refer tohttp://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/incbulkload.mspx.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 165Post-Implementation TasksThe following tasks have to be per<strong>for</strong>med to ensure the success of the data transfer. Thetasks per<strong>for</strong>med here undo the changes that were made to the schema <strong>for</strong> affecting thedata transfer, such as disabling of constraints and triggers. Chapter 9, "Developing:Databases — Unit Testing the Migration" has a more detailed discussion of per<strong>for</strong>ming thefirst two tasks as a part of testing the migrated database.1. Validate the data migration.Th e validation tasks are discussed in detail in the "Validating the Data Migration"section later in this chapter.2. Re-enable the constraints.Enable all constraints, including CHECK, PRIMARY KEY, FOREIGN KEY, andUNIQUE. Use the scripts that were created while disabling the constraints.FOREIGN KEY and CHECK constraints can be enabled using the following syntax:ALTER TABLE table_name CHECK CONSTRAINT ALLwhere table_name is the table on which the CHECK constraints have to be enabled.PRIMARY KEY and UNIQUE constraints will have to be recreated using theoriginal DDL. <strong>Oracle</strong> allows multiple rows where all columns (nullable) of aUNIQUE constraint have NULL values. SQL Server treats NULL as duplicates(instead of an unknown value) <strong>for</strong> the purpose of uniqueness. Hence creating aUNIQUE constraint would return an error if such a condition exists. Because itwould be difficult to create values, the best way to maintain the status quo wouldbe to replace the UNIQUE constraint with a trigger that accomplishes the samething.3. Recreate the indexes.The constraint indexes can be recreated using the saved scripts. Multiple indexeson a single table can be created in parallel using different client sessions.4. Enable the triggers.Identify and enable all triggers by using the following syntax:ALTER TABLE table_name ENABLE TRIGGER ALLwhere table_name is the table on which the triggers are to be enabled.5. Set the recovery model.Restore the recovery model of the SQL Server database to the original setting(normally full) by using the following syntax:ALTER DATABASE database_nameSET RECOVERY FULL6. Capture data statistics.Per<strong>for</strong>m the steps necessary to capture data statistics required by the optimizer.7. Back up the database.Create a full backup of the entire server, including the user databases. This is thefirst valid backup of the migrated database.Validating the Data MigrationThe following major tasks have to be per<strong>for</strong>med to validate the migrated data:1. Verify the data transfer.The logs or audit files <strong>for</strong> the data transfers should be checked <strong>for</strong> errors orfailures. After this processis complete, row counts of every table in the destinationSQL Server database should be matched to the source <strong>Oracle</strong> database. If any

166 Developing: Databases — <strong>Migrating</strong> the Data2.discrepancy is found in the counts, troubleshooting should include identifying themissing records and viewing the logs and audit files <strong>for</strong> error messages that canprovide reasons <strong>for</strong> the failure. The data transfer process should take intoconsideration any changes in the logical model between the source <strong>Oracle</strong>database and SQL Server. A more stringent check is difficult <strong>for</strong> large databases.More validation of the data transfer occurs in the next step as part of the dataintegrity checks.Validate the data integrity.Integrity is automatically checked when creating or enabling constraints. The WITHCHECK clause has to be used when adding constraints. Data integrity checking isthreatened when migrating databases which lack proper primary key constraintsand <strong>for</strong>eign key constraints. For more in<strong>for</strong>mation on the functionality available withcheck constraints, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_aa-az_3ied.asp.In many cases, there are no strict equivalents of <strong>Oracle</strong> datatypes in SQL Server.Hence the integrity of such data has to be tested to ensure that there is norounding or truncation, and that the exact value is stored.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 1679Developing: Databases — UnitTesting the MigrationIntroduction and GoalsThe final task to be per<strong>for</strong>med in the Developing Phase is to test the database. Becauseeverything except the core database design has been trans<strong>for</strong>med, it is very important tothoroughly test every aspect of the Microsoft® SQL Server database be<strong>for</strong>e release tothe production environment. Testing should cover the hardware, the SQL Serverinstallation, security, database objects, data, and per<strong>for</strong>mance.The descriptions of the testing process <strong>for</strong> databases and applications is divided intosmaller pieces and spread out between the Developing and Stabilizing Phases. Testing<strong>for</strong> integrity and functionality of the migrated database is covered in this chapter.Additional application-based testing of the database is per<strong>for</strong>med as part of testing theapplication. Per<strong>for</strong>mance can be verified only through the benchmarking and piloting thatis per<strong>for</strong>med in the Stabilizing Phase.Objectives of TestingThe following areas should be tested:● Physical architecture of the database. Have the data files, transaction log,tablespaces, and other items that comprise the database been created correctly?Has the SQL Server instance been properly configured?● Security. Have the logins and users been correctly created? Have the appropriatepermissions been assigned? Is the database physically secure?● Logical architecture of the database. Have the tables, views, stored procedures,triggers, and other database objects been created successfully?● Data. Have the contents of the tables been transferred correctly? Do tables containthe correct numbers of rows? Is the data valid?● Functionality. Do the stored procedures, triggers, views, and other itemscomprising Transact-SQL code operate in the same manner as the original <strong>Oracle</strong>objects?● Per<strong>for</strong>mance. Does response time and throughput meet requirements and matchuser expectations?

168 Developing: Databases — Unit Testing the MigrationTheTesting ProcessThe database is tested in three different stages of the migration:●●●Developing Phase — DatabaseIn this stage, the database is unit tested <strong>for</strong> all the components that have beenmigrated, which includes the database architecture, the schema, the users, andthe data. This type of testing is covered in the rest of this section.Developing Phase — ApplicationIn this phase, the database is tested with respect to the application support. Thisprimarily tests that all the objects required by the application are present andper<strong>for</strong>m as expected. The application-related testing is covered in the applicationdevelopment Chapters 11 through 17.Stabilizing PhaseIn the Stabilizing Phase, more thorough tests are per<strong>for</strong>med <strong>for</strong> integration,per<strong>for</strong>mance, stress, and scalability. This phase is described in Chapter 18.This section describes the testing process that is followed during the Developing Phase<strong>for</strong> the database. The testing is interspersed with the steps in the migration of thedatabase. The procedure <strong>for</strong> migration and testing is illustrated in the flowchart in Figure9.1.Figure 9.1Data migration test procedure

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 169The tasks on the left half, namely, migrating the architecture, migrating the schema,migrating the users, and migrating the data, are part of the database migration and arecovered in chapters 5 through 8. The success of these tasks is validated as databaseintegrity testing and data validation. Details regarding these two types of testing appearunder the following headings.Test Database IntegrityAfter the database schema has been created in the target database, an integrity testshould be per<strong>for</strong>med be<strong>for</strong>e starting the data migration. This should cover the physicaldatabase structure, the schema, and the schema objects.There is no tool available <strong>for</strong> comparing the integrity and validity of the SQL Serverobjects as compared to the original <strong>Oracle</strong> objects. Unit testing has to rely on theexperience and expertise of the database designers or administrators who are per<strong>for</strong>mingthe mapping. However, a true unit test would be to load data from the source objects andrun SQL with identical functionality in the two environments. Any discrepancies should beonly as a known (explainable) consequence of the migration.The following tasks are per<strong>for</strong>med to ensure database integrity:● Unit test the schema objects. The type and number of each object in the original<strong>Oracle</strong> database has to be compared to that in the SQL Server database. Queriescan be written in the two databases (<strong>Oracle</strong> and SQL Server) to produce a count ofeach type of object. However, the counts in the two solutions may not matchbecause there is no one-to-one equivalency <strong>for</strong> every object.● Verify that data elements have been created as per the mapping. The propertrans<strong>for</strong>mation of the data type and domain values of the columns — as well as anyconstraints, such as NULL and CHECK constraint on the columns — have to beverified be<strong>for</strong>e per<strong>for</strong>ming the data migration. A representative set of data from theoriginal <strong>Oracle</strong> database can be used <strong>for</strong> this purpose.● Verify that all constraints are in place. For each table having a parent-childrelationship, referential integrity is checked.● Functions, triggers, and stored procedures have been accuratelytrans<strong>for</strong>med. Stored procedures, triggers, and views can be tested by using anidentical set of representative data in the source and migrated databases.Execution of test cases against these objects should produce identical results.● Verify the data access. Additional indexes may be present in SQL Server to offsetfeatures such as fast full index scans in <strong>Oracle</strong> that can use the non-leadingcolumns of indexes. It should be verified that all objects in the original <strong>Oracle</strong>database have been successfully migrated to SQL Server. A complete set of T-SQL statements should be obtained from the application development team andeach of them verified <strong>for</strong> optimal data access paths.If the application has been migrated, running a few frequently used business transactionswould ensure whether the schema has been successfully migrated. After the correctnessof the database structure and its objects is guaranteed, data migration can proceed.Test SecurityThe security mechanisms available with SQL Server and Windows are significantlydifferent from those used by UNIX and <strong>Oracle</strong>. The difference in the authenticationmechanisms is especially important because it affects the user login process. Forexample, the requirements of password management functionality, such as aging,locking, and password strength will require that Windows authentication be used in placeof database authentication. The system privileges available in the two databases differ

170 Developing: Databases — Unit Testing the Migrationsignificantly. You must verify that only authenticated, authorized users have access to theobjects in the database. You must also verify that <strong>Oracle</strong> users and roles have beencorrectly mapped to SQL Server users and roles, and that all objects in the databasehave the appropriate access rights granted to them.Validate DataThe existence of indexes and constraints during data migration adversely affects theper<strong>for</strong>mance of the data migration. The firing of triggers can corrupt the data and produceundesirable effects. There<strong>for</strong>e, these objects have to be disabled or dropped. A negativeaspect of these actions is that data is not checked <strong>for</strong> correctness or completenessduring the migration and has to be validated after the migration. No special plans areneeded <strong>for</strong> validating data integrity. The database itself checks the integrity of the datawhen the constraints are enabled using the WITH CHECK clause. For more in<strong>for</strong>mationon check constraints in SQL Server, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_aa-az_3ied.asp.The two types of tests that have to be per<strong>for</strong>med to validate the data are discussed in the"Validating the Data Migration" section in Chapter 8.Note One of the common risks involved in data migration is the lack of a proper orcomplete set of constraints in the database. In many applications, the constraints arebuilt into the application. In such cases, the development team will have to be involvedin constructing SQL-based tests to verify data integrity by identifying such rules in theapplication.Validate the MigrationAfter data migration is complete, tests have to be per<strong>for</strong>med on the database as a whole.Testing should cover the database architecture, database objects, data, and users. Inaddition, the database connectivity, security, and per<strong>for</strong>mance have to be tested. Forin<strong>for</strong>mation on client connectivity to the database, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/adminsql/ad_1_client_5er7.asp.A discussion of the security architecture in <strong>Oracle</strong> andSQL Server is available in Appendix A: "SQL Server <strong>for</strong> <strong>Oracle</strong> Professionals." AppendixB: "Getting the Best out of SQL Server 2000 and Windows" contains several referenceson SQL Server per<strong>for</strong>mance.While in smaller databases the data migration validation can be exhaustive, in very largedatabases, some simpler tests (such as counts using various groupings) may be used.The following checks are recommended:● Develop group functions based on type of data.For example, a business-related check can be implemented by calculating the sumof the balances in all accounts.● Develop group functions based on time.● Check <strong>for</strong> record counts.● Use the application to compare the summary reports.● Check <strong>for</strong> ad-hoc control totals.For example, after ledger data of a financial application has been migrated, addingup the account numbers in that ledger has no business validity. However, this adhoccontrol total could reveal if all the data in the row has been migratedsuccessfully.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 171The SQL Server Migration Assistant offers a Migration Tester tool that verifies themigrated objects (procedures, functions, and views) by generating its own set of testdata. For more in<strong>for</strong>mation on the Migration Tester and to download it refer tohttp://www.micro soft.com/sql/migration. The beta version of this tool is available as of thedate of publishing this solution. Version 1.0 of the tool is slated to be available in June2005.A test that validates the entire migration is the running of production reports andapplication with production-quality data. The same reports should be executed againstthe original database and the migrated database using a snapshot (or copy) of productiondata. Per<strong>for</strong>mance and other vital database statistics, such as cache per<strong>for</strong>mance andlocking, can be gathered.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 17310Developing: Applications —IntroductionIntroduction and GoalsThe focus of Chapters 10 through 17 is connecting existing <strong>Oracle</strong> applications in theUNIX environment to the migrated Microsoft® SQL Server database. This chapterserves as an introduction to the application-oriented development chapters.The following list provides an overview of the content in each of the application-orienteddevelopment chapters:● Chapter 11, Developing: Applications — <strong>Oracle</strong> SQL and PL/SQL. This chapterprovides a detailed discussion of the SQL usage differences between <strong>Oracle</strong> andSQL Server. Trans<strong>for</strong>mation of PL/SQL to T-SQL is also covered.● Chapter 12, Developing: Applications — Perl. This chapter discusses thestrategies available <strong>for</strong> migrating a Perl application <strong>for</strong> use with the SQL Serverenvironment.● Chapter 13, Developing: Applications — PHP. This chapter discusses thestrategies available <strong>for</strong> migrating a PHP application <strong>for</strong> use with the SQL Serverenvironment.● Chapter 14, Developing: Applications — Java. This chapter discusses thestrategies available <strong>for</strong> migrating a Java application <strong>for</strong> use with the SQL Serverenvironment.● Chapter 15, Developing: Applications — Python. This chapter discusses thestrategies available <strong>for</strong> migrating a Python application <strong>for</strong> use with the SQL Serverenvironment.● Chapter 16, Developing: Applications — <strong>Oracle</strong> Pro*C. This chapter discusses thestrategies available <strong>for</strong> migrating a Pro*C application <strong>for</strong> use with the SQL Serverenvironment.● Chapter 17, Developing: Applications — <strong>Oracle</strong> Forms. This chapter discussesthe strategies available <strong>for</strong> migrating an <strong>Oracle</strong> Forms application <strong>for</strong> use with theSQL Server environment.No application migration will be successful without a clear understanding of the <strong>Oracle</strong>technologies that are factors during an <strong>Oracle</strong> database migration to SQL Server. Anoverview of these basic technologies and specific migrationconsiderations is discussed

174 Developing: Applications — Introductionin the following two sections. The application ecosystem can be broken into the followingtwo tiers:● Data access● Programming language and connectivity tierData access comprises the components of the application that interact with the databasedata. SQL is the language used <strong>for</strong> retrieving and manipulating the database data. Theapplication developer is responsible <strong>for</strong> ensuring that applications designed <strong>for</strong> the <strong>Oracle</strong>source database work the same way with the migrated SQL Server target database. Thechanges required vary based on the programming language support and the API librariesavailable <strong>for</strong> SQL Server. The migration of SQL and PL/SQL components to T-SQL <strong>for</strong>msa common requirement, irrespective of the changes to the rest of the application. Themigrated applications then have to be tested against the migrated SQL Server databaseto ensure their original functionality.From an application developer's perspective, <strong>Oracle</strong> and SQL Server manage data insimilar ways. The internal differences between <strong>Oracle</strong> and SQL Server are significant, butif managed properly, these differences will have minimal impact on a migratedapplication.Application Migration StrategiesThere are four different strategies <strong>for</strong> application migration that are discussed throughoutthe development chapters. These strategies include:● Interoperation. The application components remain in the UNIX environment.● Port or rewrite the application to the Microsoft .NET plat<strong>for</strong>m. The applicationis migrated to run on the .NET framework.● Port or rewrite the application to the Microsoft Win32® plat<strong>for</strong>m. Theapplication is migrated to run on the Windows® environment using the Win32 API.● Quick port using Windows Services <strong>for</strong> UNIX 3.5. The application is ported touse Interix within the Windows environment.Each of the four strategies is discussed in more detail under the following headings. One,some, or all of these solution design strategies <strong>for</strong>ms the basis of the solution conceptthat was completed during the Envisioning Phase. Even when the goal is to standardizeon the Windows plat<strong>for</strong>m, some of these strategies may be employed as intermediarysteps in a multi-phased migration.In general, .NET development is favored over Win32, but a number of recommendationsin the following chapters provide guidance on migrating to a Win32 solution. Thisin<strong>for</strong>mation is provided in cases where a Win32 migration is the most cost-effective andstraight<strong>for</strong>ward development route.For more in<strong>for</strong>mation on these migration strategies, see "Application and DatabaseMigration <strong>Solution</strong> Design Strategy" in Chapter 2, "Envisioning Phase."InteroperationIn this strategy, the application remains on the UNIX plat<strong>for</strong>m, while only the database ismigrated to SQL Server on the Windows plat<strong>for</strong>m. This strategy is employed when minorchanges can be made to the source code, connection strings, or the connectivity layer toallow <strong>for</strong> the change in the back end database.Often, an interoperation strategy is used as an interim step in a phased migration. Thisstrategy allows <strong>for</strong> the application to be quickly connected to the solution's SQL Server

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 175database with minimal risk or ef<strong>for</strong>t. However, this would not be an adequate solution ifone of the business requirements <strong>for</strong> the migration project is elimination of the UNIXenvironment.Port or Rewrite to .NET FrameworkThe .NET framework is the next generation plat<strong>for</strong>m from Microsoft <strong>for</strong> building,deploying, and running Windows applications. It provides a highly productive, standards-environment <strong>for</strong> integrating existing investments with next-based, multi-languagegeneration applications and services. When porting or rewriting, migration to the .NETplat<strong>for</strong>m is preferred because it is the current development plat<strong>for</strong>m <strong>for</strong> Windowsapplications.When migrating an application to the .NET framework, there are two different options.One is to per<strong>for</strong>m a full port of the application, and the other is to rewrite the applicationusing the .NET application programming interfaces (APIs).As of this writing, with the increased adoption of the .NET Framework in the industry, theavailability of the .NET APIs <strong>for</strong> application porting are expanding. For some of thelanguages, the drivers are in beta with support being improved to include all functionality.Verify the stability of the library and the support <strong>for</strong> all the function calls needed <strong>for</strong>SQL Server when picking a driver.A rewrite of the application is required when there is no support on the .NET plat<strong>for</strong>m <strong>for</strong>the language in use. An example of this would be an application based on <strong>Oracle</strong> Forms.The best option in this case would be to rewrite the application on Windows using VisualBasic® .NET.Rewriting an application can potentially pose challenges. It can be a time-consuming,risky, and costly option. The risk inherent in a rewrite is that the business logic or animportant functionality is inadvertently changed while rewriting the code. Careful testingand stabilizing of the rewritten application needs to be conducted to ensure properbusiness logic and functionality. The following chapters provide detailed in<strong>for</strong>mation ondatabase connectivity and the code changes needed to migrate to the SQL Serversolution. Rewriting an application requires additional knowledge beyond the scope of thisguide. Where appropriate, this guide provides references to more in<strong>for</strong>mation aboutrewriting.Port or Rewrite to Win32Th e Win32 API is the primary programming interface to the Windows operating systemfamily, including Windows® 2003. The Win32 API provides functions <strong>for</strong> processes,memory management, security, windowing, and graphics.Considering the benefits of migration to the .NET Framework, the only reason to migrateto the Win32 plat<strong>for</strong>m is that migration to .NET is not technically feasible <strong>for</strong> yourorganization. As with the previous strategy, two migration options are available whenmoving to a Win32-based plat<strong>for</strong>m. The first is to per<strong>for</strong>m a port of the application, andthe other is to rewrite the application using the Win32 APIs.A port can be used <strong>for</strong> most applications that have been developed in Java, Perl, PHP, orPython, which are available on both the UNIX and Windows plat<strong>for</strong>ms. APIs are available<strong>for</strong> SQL Server in a majority of cases. A port requires minimum changes to be done tothe source code, and a port uses UNIX-standard compatible libraries and utilities thatexist on the Windows plat<strong>for</strong>m. Compared to a port, the source code in a rewrite requiresconsiderable changes to operate in the new environment. When possible, considerrewriting the application using .NET instead of Win32.

176 Developing: Applications — IntroductionQuick Port Using Windows Services <strong>for</strong> UNIXApplications on UNIX can be rehosted to an environment on Windows (Interix) that issimilar to UNIX. Interix is a complete, POSIX-compliant (Portable Operating SystemInterface) development environment that is tightly integrated with the Windows kernel. Itis a part of the Windows Services <strong>for</strong> UNIX 3.5 product suite from Microsoft.One of the quickest migration paths possible is to port the code directly toWindows Services <strong>for</strong> UNIX. Interix allows native UNIX applications and scripts to workalongside Windows applications. The best way to view Interix is to understand it as aPOSIX-compliant version of UNIX built on top of the Windows kernel. Importantly, Interixis not an emulation of the UNIX environment on the Windows APIs. Migration usingWindows Services <strong>for</strong> UNIX involves obtaining the source code, installing it in the Interixdevelopment environment, modifying the configuration scripts and makefiles, andrecompiling the application. This strategy is referred to as a quick port. As with any othermigration strategies, the data access (SQL, PL/SQL) has to be migrated to target aSQL Server database. A quick port is preferred if the client application is closely tied toUNIX utilities that are not available on Windows. This approach cannot rely on speciallibraries <strong>for</strong> which the source code is not available. Also, quick ports usingWindows Services <strong>for</strong> UNIX cannot take advantage of most standard Windowsfunctionality.The ported application may be successful immediately, or it may require modifications toaccount <strong>for</strong> the new hardware plat<strong>for</strong>m, the target operating systems, and localconfiguration in<strong>for</strong>mation. It may not be possible to determine whether a quick port ispossible without actually conducting the port. Extensive testing of the application isessential after the port to ensure that all features have been migrated successfully.Scenarios and CasesIn the following chapters, these migration strategies are discussed in relation to commonapplication languages. All four strategies may not be available, feasible, or desirable <strong>for</strong>each of the languages. For example, per<strong>for</strong>ming a quick port usingWindows Services <strong>for</strong> UNIX is not discussed in the Perl chapter because Perl can runnatively on the Windows plat<strong>for</strong>m. Because the facilities available to Perl on Windows aremuch richer (including .NET) than those available to Perl on Windows Services <strong>for</strong> UNIX,migrating Perl applications to a Windows environment is preferred.Throughout Chapters 11 through 17, the migration strategies are divided into specificscenarios that may be similar to existing situations that you will encounter. Each scenariomay be split into individual cases that detail the various options available <strong>for</strong> a givenscenario. For example, the migration strategy of porting may best apply to your situation.In porting PHP applications to run in the Windows environment scenario, there are threecases that are discussed based on the database driver being utilized. These individualcases include detailed in<strong>for</strong>mation regarding the use of ORA, OCI8, or ODBC databasedrivers to maintain connectivity in the solution.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 17711Developing: Applications —<strong>Migrating</strong> <strong>Oracle</strong> SQLandPL/SQLIntroductionA lthough <strong>Oracle</strong> and Microsoft® SQL Server both use the ANSI SQL language, eachuses proprietary extensions to add functionality. <strong>Oracle</strong> uses PL/SQL, while SQL Serveruses Transact SQL. This cha pter focuses on application code that may need to bemodified <strong>for</strong> use with SQL Server because of these extensions.This chapter should be used in conjunction with Chapters 12 through 17. These chaptersprovide in<strong>for</strong>mation <strong>for</strong> application-specific languages, including Perl, PHP, Java, Python,Pro*C, and <strong>Oracle</strong> Forms.No application migration will be successful without a cle ar understanding of the <strong>Oracle</strong>technologies that come into play during an <strong>Oracle</strong> database migration to the SQL Serverplat<strong>for</strong>m. The strategy <strong>for</strong> application conversion is broken down into the following twosegments:● Data access, which is discussed in this chapter.● Programming language a nd connectivity tier, which are discussed in Chapters 12through 17.<strong>Migrating</strong> Data AccessThe application conversion development team is responsible <strong>for</strong> ensuring thatapplications designed <strong>for</strong> the <strong>Oracle</strong> source database work the same way with themigrated SQL Server target database.The application migration process may appearcomplicated. Be<strong>for</strong>e doing the migration ofthe <strong>Oracle</strong> production database, the DBA or application developer should install aSQL Server test database. Applications can then be modified and tested, if necessary, toensure their original functionality with the SQL Server database. Testing is necessarybecause of the core differences between <strong>Oracle</strong> and SQL Server.There are some architectural differences between each RDBMS. The terminology usedto describe <strong>Oracle</strong> architecture often has a completely different meaning in MicrosoftSQL Server; <strong>for</strong> example, the term database has a different meaning. Additionally, both

178 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL<strong>Oracle</strong> and SQL Server have made many proprietary extensions to the SQL-92 standard.These extensions are discussed throughout this chapter.F rom an application develope r's perspective , <strong>Oracle</strong> and SQL Server manage data insimilar ways. The internal differences between <strong>Oracle</strong> and SQL Server are significant, butif managed properly, have mi nimal impact on a migrated application.The most signif icant migration issue that confronts the developer is the implementation ofthe SQL-92 SQL language standard and the extensions that each RDBMS has to offer.Some developers use only st andard SQL language statements, preferring to keep theirprogram code as generic as possible. Generally, this means restricting program code tothe entry-level SQL-92 standard, which is implemented consistently across manydatabase products, including <strong>Oracle</strong> and SQL Server.Using RDBMS-specific extensions might produce unneeded complexity in the programcode during the migration. For example, <strong>Oracle</strong>'s DECODE function is a nonstandardSQL extension specific to Ora cle. The CASE expression in SQL Server is notimplemented in all database products.B oth the <strong>Oracle</strong> DECODE and the SQL Server CASE expressions can per<strong>for</strong>msophisticated conditional evaluations from within a query. The alternative to using thesefunctions is to per<strong>for</strong>m the function programmatically, which could require substantiallymore data be retrieved from the RDBMS.SQL has seen several sets of standards implemented and embraced by AmericanNational Standards Institute ( ANSI) and International Standards Organization (ISO).Although there are several enhancement releases of each standard set, the majorreleases are S QL-86, SQL-89 (also called SQL1), SQL-92 (also called SQL2) and SQL-99 (also called SQL3), with SQL-99 merging ANSI and ISO standards into one set.There are four levels or sets of features in SQL-92: entry-level, transitional, intermediate,and full. SQL Server 2000 Transact-SQL complies with the entry level of the SQL-92standard, and it supports many additional features from the intermediate and full levels ofthe standard.SQL-99 has two sets of features: core and non-core. <strong>Oracle</strong> 9i fully supports a majority ofthe core SQL-99 features, and it partially supports the n on-core features.T he SQL-92 entry-level feature set is very similar to the SQL-99 core feature set, whichm eans <strong>Oracle</strong> 9i supports entry level feature s of SQL-92 entry level. Even though bothsupport many of t he standard features, <strong>Oracle</strong> and SQL Server do not use the samesyntax. In addition, each RDBMS has its own unique functionality and extensions.<strong>Oracle</strong> SQL statements and Microsoft SQL Server T-SQL are compatible with each otherin several areas with minimal changes in the syntax. All the basic and advancedfunctionality furnished by <strong>Oracle</strong> can be achieved in SQL Server with ease.Though both these RDBMSs can be used to build robust and efficient systems, they differr adically in the administrative functions and plat<strong>for</strong>m dependence.This section shows how to arrive at T-SQL equivalents <strong>for</strong> the most common <strong>Oracle</strong> SQLu sages, and it includes comprehensive coverage of all a spects of the SQL languagei mplementation.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 179Sample TablesThe following tables are used in all the exa mples in this chapter.Table 11.1: Category TableCOLUMN_NAME DATATYPE CONSTRAINTCATEGORYID VARCHAR(10) Primary KeyCATEGORYNAMEDESCRIPTIONTable 11.2: Customer TableVARCHAR(40)VARCHAR(50)COLUMN_NAME DATATYPE CONSTRAINTCUSTOMERID VARCHAR(10) Primary KeyCOMPANYNAMECONTACTNAMECONTACTTITLEADDRESSCITYREGIONPOSTALCODECOUNTRYPHONEFAXTable 11.3: Employee TableVARCHAR(40)VARCHAR(40)VARCHAR(40)VARCHAR(50)VARCHAR(30)VARCHAR(30)VARCHAR(10)VARCHAR(30)NUMERIC(10.0)NUMERIC(10.0)COLUMN_NAME DATATYPE CONSTRAINTEMPLOYEEID VARCHAR(10) Primary KeyLASTNAMEFIRSTNAMETITLETITLEOFCOURTESYBIRTHDATEHIREDATEADDRESSCITYPOSTALCODECOUNTRYVARCHAR(40)VARCHAR(40)VARCHAR(40)VARCHAR(50)DATETIMEDATETIMEVARCHAR(40)VARCHAR(30)NUMERIC(10.0)VARCHAR(10)REPORTINGTO VARCHAR(10) Foreign Key

180 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLTable 11.4: OrderMaster TableCOLUMN_NAME DATATYPE CONSTRAINTORDERID VARCHAR(10) Primary KeyCUSTOMERID VARCHAR(10) Foreign KeyEMPLOYEEID VARCHAR(10) Foreign KeyORDERDATEREQUIREDDATESHIPPEDDATESHIPVIAFREIGHTDATETIMEDATETIMEDATETIMEVARCHAR(30)NUMERIC(10.0)SHIPNAMEVARCHAR( 30)SHIPADDRESSSHIPCITYSHIPREGIONSHIPPOSTALCODETable 11.5: OrderDetails TableVARCHAR(30)VARCHAR(10)VARCHAR(30)VARCHAR(10)COLUMN_NAME DATATYPE CONSTRAINTORDERID VARCHAR(10) Foreign KeyPRODUCTID VARCHAR(10) Foreign KeyUNITPRICEQUANTITYDISCOUNTTable 11.6: OrderPrice TableNUMERIC(10.2)NUMERIC(10.0)NUMERIC(10.0)COLUMN_NAME DATATYPE CONSTRAINTORDERID VARCHAR(10) Foreign KeyPRODUCTID VARCHAR(10) Foreign KeyREVISEDPRICEREVISEDONTable 11.7: Product TableNUMERIC(10.2)DATETIMECOLUMN_NAME DATATYPE CONSTRAINTPRODUCTID VARCHAR(10) Primary KeyPRODUCTNAMEVARCHAR(30)SUPPLIERID VARCHAR(30) Foreign KeyCATEGORYID VARCHAR(10) Foreign KeyQUANTITYPERUNITUNITPRICENUMERIC(10.0)NUMERIC(10.2)UNITINSTOCK NUMERIC(10.0)UNITSONORDERREORDERLEVELDISCONTINUEDNUMERIC(10.0)NUMERIC(10.0)NUMERIC(10.0)

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 181Table 11.8: Shippers TableCOLUMN_NAME DATATYPE CONSTRAINTSHIPPERID VARCHAR(10) Primary KeyCOMPANYNAMEVARCHAR(30)PHONENUMERIC(10.0)Table 11.9: Suppliers TableCOLUMN_NAME DATATYPE CONSTRAINTSUPPLIERID INT DENTITY Primary KeyCOMPANYNAMEVARCHAR(30)CONTACTNAMEVARCHAR(30)CONTACTTITLEVARCHAR(40)ADDRESSVARCHAR(40)CITYVARCHAR(30)POSTALCODENUMERIC(10.0)COUNTRYVARCHAR(40)PHONENUMERIC(10)FAXNUMERIC(10)Table 11.10: ShippedOrders TableCOLUMN_NAME DATATYPE CONSTRAINTORDERID VARCHAR(10) Foreign KeyCUSTOMERID VARCHAR(10) Foreign KeyEMPLOYEEID VARCHAR(10) Foreign KeyORDERDATEDATETIMEREQUIREDDATEDATETIMESHIPPEDDATEDATETIMESHIPVIAVARCHAR(30)FREIGHTNUMERIC(10.0)SHIPNAMEVARCHAR(30)SHIPADDRESSVARCHAR(30)SHIPCITYVARCHAR(10)SHIPREGIONVARCHAR(30)SHIPPOSTALCODE VARCHAR(10)Migration Process OverviewRecommended high-level steps <strong>for</strong> the migration process include:1. Extraction of data access. Identify the SQL statements used in the applicationand make sure it will work with SQL Server. If some SQL statements are database-specific, rewrite them <strong>for</strong> SQL Server.2. Transaction management. Accommodate changes in the transaction because ofthe migration.

182 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL3. Fetch strategy. Pay special attention to cursor management and rewrite it ineasier way by making use of effective cursor management available inSQL Server 2000. Try to avoid cursors being used by <strong>Oracle</strong> application ifpossible.4. Subprograms conversion. Identify all the procedures, functions, and triggers andrewrite in T-SQL.5. Job scheduling. Batch jobs that are written in PL/SQL should be rewritten.6. Interface file conversion. For any inbound (text file -> table) jobs, pay attention tothe interface file and make sure there are no problems with the current <strong>for</strong>mat ofthe interface file. Pay attention to any outbound interface as well. Keep in mind thatthe date <strong>for</strong>mat between <strong>Oracle</strong> and SQL Server are different.7. Workflow automation. Workflow automation is implemented in the application.The creationof Mail Ids is required.8. Per<strong>for</strong>man ce tuning. Tune the T-SQL statements wherever it is required.During these steps, the developer should look at the application code and startconverting <strong>Oracle</strong>-specific code into T-SQL compatible code. All major <strong>Oracle</strong> commandsand how to convert them into T-SQL are discussed in detail throughout this chapter.<strong>Oracle</strong> and SQL Server both provide extensive support <strong>for</strong> XML, whose migration is notwithin the scope of this guide. For details on the SML support available in SQL Serverrefer to http://msdn.microsoft.com/library/default.asp?url=/library/enus/architec/8_ar_cs_9oj8.asp.Step 1: Extraction of Data AccessThe first step is to identify the SQL used in the application. SQL includes DataManipulation Language (DML), Data Query Language (DQL or, simply, queries), andoperators. The majority of SQL syntax is common between <strong>Oracle</strong> and SQL Server withminor variations.There are several different types of in<strong>for</strong>mation in the SQL code that will need to beidentified. If these types do not comply with the specifications and syntax of SQL Server,this in<strong>for</strong>mation will need to be modified. An in-depth discussion of the following topics isincluded in this section:● Operators● Functions● Queries● Data Manipulation Language (DML)OperatorsOperators are used <strong>for</strong> many different purposes in SQL. Table 11. 11 displays theseo perators by type.Table 11.11 : Commonly Used OperatorsOperator Type ExampleArithmetic +, -, *, /Comparison =, , =LogicalAND,OR, NOT , XOR

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 183These operators may play a role in the SELECT clause of a query ( <strong>for</strong> reportingpurposes), or they may be used in a PL/SQL block <strong>for</strong> per<strong>for</strong>ming various calculations tocomplete the transaction.The in<strong>for</strong>mation under the following heading describes how each of the operators is usedi n <strong>Oracle</strong> and SQL Server.Operator PrecedenceWhen multiple arithmetic operators are used in a single query, the processing of theoperation takes place according to the precedence of the operators. The precedencel evel of arithmetic operators in an expression is multiplication (*), division (/), modulo (%),addition (+), concatenation (+), and subtraction (-). Equations contained withinparentheses take precedence and are per<strong>for</strong>med first. The order of execution is from leftto right.Concatenation OperatorsConcatenation is per<strong>for</strong>med differently between SQL Server and <strong>Oracle</strong>. Theconcatenation operator (<strong>for</strong> character strings) used in <strong>Oracle</strong> is “||” or CONCAT(string1,string2). The following example shows this syntax <strong>for</strong> each usage. Each of thesestatements will produce the same result in <strong>Oracle</strong>.SELECT FI RSTNAME || LASTNAME NAME FROM EMPLOYEESELECT CONCAT(FIRSTNAME, LASTNAME) NAME FROM EMPLOYEE;In these statements, the first name is concatenated with the last name and the label <strong>for</strong>the field is NAME. SQL Server uses a different operator <strong>for</strong> concatenation. Theconcatenation op erator (<strong>for</strong> character strings) used in SQL Server is “+.” The followingexample shows the first name concatenated with the last name, along with empty spacein between the names. The label<strong>for</strong> the field is NAME.SELECT FIRSTNAME + ‘ ‘ + LASTNAME As NAME FROM EMPLOYEEComparison OperatorsConditions are evaluated using comparison operators, including "=", ">" and ">=", “

184 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLOperator MeaningALL TRUE if all of a set of comparisons are TRUEANDTRUE if both Boolean expressions are TRUEANY TRUE if any one of a set of comparisons is TRUEBETWEEN TRUE if the operand is within a rangeEXISTSINTRUE if a subquery contains any rowsTRUE if the operand is equal to one of a list of expressionsLIKE TRUE if the opera nd matches a patternNOT Reverses the value of any other Boolean operatorSOMEIS NULLTRUE if some of a set of comparisons are TRUETRUE if operand is NULLIS NOT NULL TRUE if operand is not NULLORDatatype PrecedenceTRUE if either Boolean express ion is TRUEEach column valu e and constant in a SQL statement has a datatype that is associatedwith a specific storage <strong>for</strong>mat, constraints, and a valid range of values. When a table iscreated, a datatype is specified fo r each column.Arithmetic operations per<strong>for</strong>med on columns and constants of different datatypes, suchas INT and SMALLINT, are called as mixed mode arithmetic operations. In mixed modearithmetic operations, the lower d atatype value is converted into a h igher datatype valueaccording to datatype precedence.Datatype conversion is often needed to attain compatibility during calculation,concatenation, or comparison of values.FunctionsIn many places, built-in functions are used <strong>for</strong> conversion and <strong>for</strong> o ther purposes. Somecommonly used functions are defined and discussed here with examples provided <strong>for</strong>their use. Some f unctions that are available in <strong>Oracle</strong> are not available inSQL Server 2000 or earlier versions. However, those functions canbe written inSQL Server with the same name and the same fun ctionality. They are called user-definedfunctions. Some user-defined functions are described later in this chapter.Number and Mathematical FunctionsTable 11.13 details the differences in syntax and usage between <strong>Oracle</strong> and SQL Server.These functions are all mathematically based.Table 11.13: Mathematical Functions in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong> Description <strong>Oracle</strong> SQL Server SQL ServerFunction Example Function ExampleABSReturns the ABS (-20) ABS ABS(-20)absolute valueof nACOSReturns cosineof n. n must bebetween –1and 1ACOS (.4) ACOS ACOS(.4)

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 185CEIL Returns the CEIL (12.3) CEILING CEILING (12.3)smallest returns 13returns 13integer greaterthan nFLOOR Returns the FLOOR (12.3) FLOOR FLOOR (12.3)smallestinteger smallerthan nreturns 12returns 12MODReturns the MOD (12,5) % 12%5 returns 2reminder of mdivided by nreturns 2POWER Computes thevalue ofPOWER (10,5)returns 100000POWER POWER (10,5)returns 100000argument 1raised to thepower ofargument 2ROUNDReturns thenearest valueof the decimalas per theprecisionspecifiedTruncates thedecimalROUND(10.125,2)ROUNDROUND(10.125,2)returns 10.13 returns 10.130TRUNC TRUNC (12.54) CONVERTreturns 12CONVERT(INTEGER,12.54) returns12Character FunctionsTable 11.14 details the differences in syntax and usage between <strong>Oracle</strong> and SQL Server.These functions are all related to text strings and characters.Table 11.14: Character Functions in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong>FunctionDescription <strong>Oracle</strong>ExampleCHR Returns the CHR (65)character <strong>for</strong> returns Athe ASCII valueCONCAT Appends two CONCATstring value s ('Tom', 'Mike')return TomMikeINITCAP GivesINITCAP ('terryuppercase toadams') returnsthe title (TitleTerry Adamscase)SQL Server SQL ServerFunction ExampleCHAR CHAR (65)returns A+ 'Tom' + 'Mike'returns TomMikeNo equivalentfunctionAn algorithmcan be written<strong>for</strong> equivalentfunctionality

186 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLLOWERReturns thelowercase ofthe stringLOWER ('TIM')returns timLOWERLTRIM Trims the LTRIM (' TIM') LTRIMleading spacesin a givenreturns 'TIM'StringREPLACE Replaces a REPLACEREPLACEmatching String ('TIM','I','o')with a new returns ToMString in agiven StringRPADPad characters RPADNo equivalentto the right side ('USA',5,'*')functionof the string returns USA**LPADSOUNDEXSUBSTRPad charactersto the left sideof the stringSOUNDEXfunction letsyou to comparewords that arespelleddifferently butsound alikeTo take only afew charactersLPAD('USA',5,'*')returns **USASOUNDEX('CHARLOTTE') is equal toSOUNDEX('CHARLOTE')SUBSTRING('Bikes', 1,4)No equivalentfunctionSOUNDEXSUBSTRINGLOWER('TIM')returns timLTRIM(' TIM')returns 'TIM'REPLACE('TIM','i','o') returnsToMAn algorithmcan be written<strong>for</strong> equivalentfunctionalityAn algorithmcan be written<strong>for</strong> equivalentfunctionalitySOUNDEX('CHARLOTTE') is equal toSOUNDEX('CHARLOTE')SUBSTRING('Bikes', 1,4)from a string returns Bike returns BikeTRANSLATE Translate a This function in No equivalent An algorithmcharacter <strong>Oracle</strong> is used function can be writtenstring. Used <strong>for</strong> to convert a<strong>for</strong> equivalentencryption string intoanother <strong>for</strong>m.functionalityLow level ofencryption isdone usingthis.TRIMUPPERASCIITo remove theleading andtrailing spacesof a stringReturns theuppercase ofthe stringReturns the ASCII ('A')ASCII value of returns 65TRIM (' THISIS TEST ')returns THIS ISLTRIM andRTRIM can becombinedRTRIM(LTRIM(' THIS IS TEST')) returns THISTESTIS TESTUPPER ('tim') UPPER UPPER('tim')returns TIMreturns TIMASCIIASCII('A')returns 65

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 187the characterINSTRLENGTHUsed to findthe location ofa sub string ora characterinside a stringReturns thelength of agiven stringINSTR('NORTHCAROLINA','OR', 1) returns 2LENGTH('TOM') returns3CHARINDEXLENCHARINDEX('OR','NORTHCAROLINA', 1)returns 2LEN ('TOM')returns 3Date FunctionsTable 11.15 details the differences in syntax and usage between <strong>Oracle</strong> and SQL Server.These functions are all date-based.Table 11.15: Date Functions in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong> Description <strong>Oracle</strong> SQL Server SQL ServerFunctionExample Function ExampleADD_MONTHSNEXT_DAYSYSDATETO_CHARTO_DATETo add numberof months <strong>for</strong> agiven dateNEXT_DAYfunction returnsthe firstweekday laterthan thepassed dateReturns thecurrent dateTO_CHAR isused when anINTEGER orDATE valueneeds to beconverted intoStringAny givenstring in a validdate <strong>for</strong>mat canbe convertedinto DATEDatatypeADD_MONTHS ('15-NOV-2004', 1)returns '15-DEC-2004'NEXT_DAY(SYSDATE,'FRIDAY')returns thedate of thecoming FridaySYSDATEreturns thecurrent dateTO_CHAR(sysdate,'MM/DD/YY')TO_DATE ('12-MAY-2003','DD-MON-YYYY')DATEADDNo equivalentfunctionDATEADD(MM, 1,'15-NOV-2004' )returns '15-DEC-2004'An algorithmcan be written<strong>for</strong> equivalentfunctionalityGETDATE () GETDATE ()returns thecurrent datewith time stampCAST orCONVERTCASTCONVERT(char, getdate(), 1) returnsdate inMM/DD/YY<strong>for</strong>mat.CAST ('12-MAY-200312:00:00' asDATETIME)The CONVERT function is used in SQL Server to change the date <strong>for</strong>mat. This isequivalent to the TO_CHAR function of <strong>Oracle</strong>. CONVERThas three parameters. The

188 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLfirst parameter is datatype. The second parameter is <strong>for</strong> the column to be <strong>for</strong>matted. Thethird parameter is the desired <strong>for</strong>mat. Please see the list of <strong>for</strong>mats and thecorresponding <strong>for</strong>mula in Table 11.16.Table 11.16: CONVERT Function Formats in SQL ServerWITH CENTURY (YYYY)INPUT/OUTPUT0 OR 100 (*) MON DD YYYY HH:MIAM (OR PM)101 MM/DD/YY102 YY.MM.DD103 DD/MM/YY104 DD.MM.YY105 DD-MM-YY106DD MON YY107 MON DD, YY108 HH:MM:SS9 OR 109 (*)DEFAULT + MILLISECONDS110MON DD YYYY HH:MI:SS:MMMAM (ORPM)MM-DD-YY111 YY/MM/DD112 YYMMDD13 OR 113 (*) DD MON YYYY HH:MM:SS:MMM(24H)114 HH:MI:SS:MMM(24H)20 OR 120 (*) YYYY-MM-DD HH:MI:SS(24H)21 OR 121 (*) YYYY-MM-DD HH: MI: SS.MMM (24H)130* DD MON YYYY HH:MI:SS:MMMAM131* DD/MM/YY HH:MI:SS:MMMAMConditional FunctionsConditional functions are used to compare values or to evaluate a Boolean expression.Table 11.17 compares these functions between <strong>Oracle</strong> and SQL Server.Table 11.17: Conditional Functions in <strong>Oracle</strong> and SQL<strong>Oracle</strong> Description <strong>Oracle</strong> SQL Server SQL ServerFunction Example Function ExampleNVL To return a NVL (SALARY, ISNULL ISNULLdefault value if 0) returns 0 if(SALARY, 0)the expression the column returns 0 if theis nullvalue (SALARYcolumn) is nullcolumn value(SALARYcolumn) is nullNVL2 To return a NVL2 (Salary, CASECASE SALARYvalue if the Salary*2, 0) WHEN nullexpression isnull or nullreturns twotimes thesalary if not nulland 0 if nullTHEN 0ELSESALARY*2END

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 189NULLIFReturns a nullvalue if the twospecifiedexpressionsare equivalentNULLIF(SYSDATE,SYSDATE)returns NULLNULLIFNULLIF(GETDATE (),GETDATE ())returns NULLDECODE Used to DECODE(DIS CASECASEevaluate the CONTINUED, DISCONTINUEvalues with "if- 0, 'No', 1, 'Yes',Delse" logic. 'NA')WHEN 0 THEN'No'WHEN 1 THEN'Yes'ELSE 'NA'ENDCASEUsed toevaluate thevalues with "if-CASEdiscontinuedWHEN 0 THENCASECASEdiscontinuedWHEN 0 THENelse" logic. 'No''No'WHEN 1 THEN'Yes'ELSE 'NA'ENDWHEN 1 THEN'Yes'ELSE 'NA'ENDQueriesThe SELECT statement is used to query the database and retrieve data. SELECT can becombined with some DDL and DML statements to per<strong>for</strong>m relational operations. Thefollowing different clauses commonly used with SELECT in <strong>Oracle</strong> and SQL Server arediscussed in the remainder of this section.● Simple queries● Joins● Database links● Group by● Case● Set operators● RownumOptimizer hints are not covered in this guidance. Both <strong>Oracle</strong> and SQL Server use costthatcan be used to influence the optimizer. Thebased optimizers and offer hintsoptimizer hints used with <strong>Oracle</strong> are not available in SQL Server. For the various types ofhints available in SQL Server refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/acdata/ac_8_qd_03_8upf.asp.Simple QueriesA simple query is defined as a SELECT statement that retrieves data from a single tablewith or without filter condition. Becausethis is a standard command, there are nodifferences in syntax or usage between <strong>Oracle</strong> and SQL Server. The following example isa valid statement <strong>for</strong> both <strong>Oracle</strong> and SQL Server.

190 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLSELECT * FROM CUSTOMER;JoinsJoins play a major role when meaningful in<strong>for</strong>mation needs to be retrieved from morethan one table. Often, reports or intricate queries require data from two or more tables.The data from multiple tables must be logically related. SQL combines data from multipletables using joins into a single result set.Joins can be of following types:● Inner join● Equi-join● Non-equi join●●Outer join● Left outer join● Right outer join● Full outer joinSelf-joinInner JoinInner join is the normal join that is per<strong>for</strong>med among tables to fetch the matching data.Inner join can be either an equi-join or non-equi join. Both equi and non-equi join areexplained under the following headings.Equi-JoinAn equi-join equates fields from two or more tables to fetch matching data from the tablesselected. There is considerable difference in the syntax of an equi-join between <strong>Oracle</strong>and SQL Server.The standard <strong>Oracle</strong> equi-join syntax is shown in the following example:SELECT TABLE1. FIELD1, TABLE2.FIELD1, TABLE2.FILED2FROM TABLE1, TABLE2WHERE TABLE1.FIELD3 = TABLE2.FIELD3AND TABLE1.FIELD4 = TABLE2.FIELD4<strong>Oracle</strong> 9i equi-joins are slightly different; the syntax is modified to comply with the ANSIstandard. The <strong>Oracle</strong> 9i syntax is shown in the following example:SELECT TABLE1.FIELD1, TABLE2.FIELD1, TABLE2.FIELD2FROM (TABLE1 INNER JOIN TABLE2 ON TABLE1.FIELD3 = TABLE2.FIELD3AND TABLE1.FIELD4 = TABLE2.FIELD4)The SQL Server syntax is also slightly different, and it is shown in the following example:SELECT TABLE1.FIELD1, TABLE2.FIELD1, TABLE2.FIELD2FROM TABLE1 INNER JOIN TABLE2ON TABLE1.FIELD3_=_TABLE2.FIELD3AND TABLE1.FIELD4 = TABLE2.FIELD4For example, a company needs to create a report with the following in<strong>for</strong>mation:● Product name● Price● Supplier’s company name● Category name

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 191For a product produced by the example company, the corresponding supplier’s companyname and the corresponding category name have to be displayed. The PRODUCT tablehas SUPPLIERID and CATEGORYID, but not their corresponding names. Procedures<strong>for</strong> using the PRODUCTNAME <strong>for</strong> <strong>Oracle</strong>, <strong>Oracle</strong> 9i, and SQL Server are shown in thefollowing examples.In <strong>Oracle</strong>, the inner join will provide the needed in<strong>for</strong>mation:SELECT A.PRODUCTNAME, A.UNITPRICE, B.COMPANYNAME, C.CATEGORYNAMEFROM PRODUCT A, SUPPLIERS B, CATEGORY CWHERE A.SUPPLIERID = B.SUPPLIERIDAND A.CATEGORYID = C.CATEGORYIDThe following code produces the same inner join in <strong>Oracle</strong> 9i:SELECT A.PRODUCTNAME, A.UNITPRICE, B.COMPANYNAME, C.CATEGORYNAMEFROM (PRODUCT A INNER JOIN SUPPLIERS BON A.SUPPLIERID = B.SUPPLIERID INNER JOIN CATEGORY CON A.CATEGORYID = C.CATEGORYID)The SQL Server syntax is the same as the preceding <strong>Oracle</strong> 9i syntax.Self JoinsSelf joins can be used when one row in a table relates itself with other rows in the sametable. That is, the same table is used twice <strong>for</strong> comparison. The same table must beexhibited as two different tables by using different aliases. This function is available in<strong>Oracle</strong> and SQL Server, though there are slight differences in syntax. The syntax <strong>for</strong><strong>Oracle</strong> self joins is provided here:SELECT A.FIELD1, A.FIELD2, B.FIELD1, B.FIELD2FROM TABLE1 A, TABLE1 BWHERE A.FIELD1 = B.FIELD1AND A.FIELD2 < B.FIELD2The SQL Server syntax is shown in the following example. Note the differences in thethird and fourth lines of the statement.SELECT A.FIELD1, A.FIELD2, B.FIELD1, B.FIELD2FROM TABLE1 A JOIN TABLE1 BON A.FIELD1 = B.FIELD1WHERE A.FIELD2 < B.FIELD2Con sider a case in which the result set must return a list of all companies in the same cityas the company “ABC Inc.”In <strong>Oracle</strong>, the statement would appear as:SELECT B.COMPANYNAMEFROM CUSTOMER A, CUSTOMER BWHERE A.CITY = B.CITYAND A.COMPANYNAME = 'ABC Inc'In SQL Server, the same result set can be returned using the following statement:SELECT B.COMPANYNAMEFROM CUSTOMER A JOIN CUSTOMER BON A.CITY = B.CITYWHERE A COMPANYNAME = 'ABC Inc'

192 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLNon-Equi JoinsNon -equi joins are used when there is not a direct link criterion between the tables. It issimply a join where the joining criteria are anything other than “=.” The difference in thesyntax between <strong>Oracle</strong> and SQL Server in cases of non-equi join is a minor difference inthe operators used to notify the non-equi join. The <strong>Oracle</strong> syntax is provided in thefollowing example:SELECT A.FIELD1, A.FIELD2, A.FIELD3, B.FIELD4FROM TABLE1 A, TABLE2 BWHERE A.FIELD1 = B.FIELD1AND A.FIELD2 B.FIELD2The SQL Server syntax is provided in the following example. Note the use of the innerjoin operator.SELECT A.FIELD1, A.FIELD2, A.FIELD3, B.FIELD4FROM TABLE1 A INNER JOIN TABLE2 BON A.FIELD1 = B.FIELD1WHERE A.FIELD2 B.FIELD2For example, imagine a case where there is a need to retrieve those products listedunder the same category but from different suppliers. In <strong>Oracle</strong>, the statement can becreated as follows:SELECT A.PRODUCTID, A.PRODUCTNAME, A.UNITPRICEFROM PRODUCT A, PRODUCT BWHERE A.CATEGORYID = B.CATEGORYIDAND A.SUPPLIERID B.SUPPLIERIDThe same result can be accomplished in SQL Server, as shown in the following example:SELECT A.PRODUCTID, A.PRODUCTNAME, A.UNITPRICEFROM PRODUCT A INNER JOIN PRODUCT BON A.CATEGORYID = B.CATEGORYIDAND A.SUPPLIERID B.SUPPLIERIDOuter JoinsA join is termed as outer join when the result set contains all the rows from one table andonly the matching rows from the other table.An outer join can be a left outer join or a right outer join. Outer join syntax in <strong>Oracle</strong> andSQL Server remained different until the release of <strong>Oracle</strong> 9i. Thereafter, both follow ANSIstandards of using INNER JOIN or OUTER JOIN in words instead of operators.All rows are retrieved from the left table referenced with a left outer join. Here, the outerjoin operator (+) is placed beside the table that is to the left of the "=" operator during thejoin.● <strong>Oracle</strong> — left outer joinThe syntax <strong>for</strong> left outer join is as follows:SELECT A.FIELD1, A.FIELD2, B.FIELD1, B.FIELD2FROM TABLE1 A, TABLE1 BWHERE A.FIELD1(+) = B.FIELD1Example <strong>for</strong> left outer join is:●SELECT A.PRODUCTNAME, A.CATEGORYID, B.COMPANYNAME, B.CONTACTNAMEFROM PRODUCT A, SUPPLIERS BWHERE A.SUPPLIERID(+) = B.SUPPLIERID<strong>Oracle</strong> 9i — left outer join

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 193The ANSI syntax <strong>for</strong> left outer join is as follows:SELECT A.FIELD1, A.FIELD2, B.FIELD1, B.FIELD2FROM TABLE1 A LEFT OUTER JOIN TABLE2 BON A.FIELD1 = B.FIELD1Example <strong>for</strong> ANSI compliant left outer join is:●SELECT A.PRODUCTNAME, A.CATEGORYID, B.COMPANYNAME, B.CONTACTNAMEFROM PRODUCT A LEFT OUTER JOIN SUPPLIERS BON A.SUPPLIERID = B.SUPPLIERIDSQL Server — left outer joinThe syntax <strong>for</strong> left outer join is as follows:SELECT A.FIELD1, A.FIELD2, B.FIELD1, B.FIELD2FROM TABLE1 A LEFT OUTER JOIN TABLE2 BON A.FIELD1 = B.FIELD1Example <strong>for</strong> left outer join is:SELECT A.PRODUCTNAME, A.CATEGORYID, B.COMPANYNAME, B.CONTACTNAMEFROM PRODUCT A LEFT OUTER JOIN SUPPLIERS BON A.SUPPLIERID = B.SUPPLIERIDAll rows are retrieved from the right table referenced in a right outer join. A right outer joinis used to furnish null rows to the right side table used during the Join condition.● <strong>Oracle</strong> — right outer joinThe syntax <strong>for</strong> right outer join is as follows:SELECT A.FIELD1, A.FIELD2, B.FIELD1, B.FIELD2FROM TABLE1 A, TABLE1 BWHERE A.FIELD1 = B.FIELD1(+)Example <strong>for</strong> right outer join is:●SELECT A.PRODUCTNAME, A.CATEGORYID, B.COMPANYNAME, B.CONTACTNAMEFROM PRODUCT A, SUPPLIERS BWHERE A.SUPPLIERID = B.SUPPLIERID(+)SQL Server — right outer joinThe syntax <strong>for</strong> right outer join is asfollows:SELECT A.FIELD1, A.FIELD2, B.FIELD1, B.FIELD2FROM TABLE1 A RIGHT OUTER JOIN TABLE2 BON A.FIELD1 = B.FIELD1Example <strong>for</strong> right outer join is:SELECT A.PRODUCTNAME, A.CATEGORYID, B.COMPANYNAME, B.CONTACTNAMEFROM PRODUCT A RIGHT OUTER JOIN SUPPLIERS BON A.SUPPLIERID = B.SUPPLIERIDAll row s from both tables are returned in a full outer join.• <strong>Oracle</strong> — full outer join<strong>Oracle</strong> does not have a separate outer join syntax. The following shows anexample <strong>for</strong> full outer join:SELECT A.PRODUCTNAME, A.CATEGORYID, B.COMPANYNAME, B.CONTACTNAMEFROM PRODUCT A, SUPPLIERS BWHERE A.SUPPLIERID = B.SUPPLIERID(+)UNION

194 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLSELECT A.PRODUCTNAME, A.CATEGORYID, B.COMPANYNAME, B.CONTACTNAMEFROM PRODUCT A, SUPPLIERS BWHERE A.SUPPLIERID(+) = B.SUPPLIERID• SQL Service — full outer joinThe syntax <strong>for</strong> full outer join is as follows:SELECT A.FIELD1, A.FIELD2, B.FIELD1, B.FIELD2FROM TABLE1 A FULL OUTER JOIN TABLE2 BON A.FIELD1 = B.FIELD1Example <strong>for</strong> full outer join is:SELECT A.PRODUCTNAME, A.CATEGORYID, B.COMPANYNAME, B. CONTACTNAMEFROM PRODUCT A FULL OUTER JOIN SUPPLIERS BON A.SUPPLIERID = B.SUPPLIERIDSubqueriesA subquery is a normal query that is nested inside another query using parentheses.Subqueries are used to retrieve data from tables that depend on the values on the sametable or a different table. A statement containing a subquery is called a parent statement.A subquery can be commonly found in the FROM and WHERE clauses of a SELECTstatement. A subquery in the FROM clause is also called an inline view. Inline views inSQL Server are similar to those in <strong>Oracle</strong>. In SQL Server, inline views have to be aliasedin all cases.Subqueries found in the WHERE clauses are called nested queries. Subqueries may benested in other subqueries. T-SQL queries can use a maximum of 256 tables, includingall subqueries, and a maximum of 32 levels of nesting. In contrast, <strong>Oracle</strong> allows 255levels of nesting. It is uncommon to use more than two or three levels of nesting inqueries. SQL Server supports most implementations of the nested query in <strong>Oracle</strong>.Examples of nested queries are found throughout this chapter. SQL Server, however,does not support the ordered set as shown in the following example:SELECT productid, revisedpriceFROM OrderPriceWHERE (orderid, productid) IN (SELECT orderid, productidFROM OrderDetails)In such cases, the query can be converted into one using joins instead of the nestedquery.SELECT OP.productid, OP.revisedpriceFROM OrderPrice OP INNER JOIN OrderDetails ODON OP.orderid = OD.orderidAND OP.productid = OD.productidA nested query in which the nested query references columns in the parent table is calleda correlated subquery. A correlated subquery is executed once <strong>for</strong> each row in the parentstatement. Because <strong>Oracle</strong> syntax and SQL Server syntax are similar, examples are notprovided here.Grouping Result Set<strong>Oracle</strong> and SQL Server provide a method of grouping the result set using the GROUP BYclause. The GROUP BY clause summarizes the result set into the groups defined in thequery using aggregate functionssuch as AVG or SUM. Using the HAVING clause can

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 195further filter the result set by comparing it with the aggregate function's result. TheHAVING clause without a GROUP BY clause behaves like a simple WHERE condition.HAV ING clauses are used with aggregation functions and cannot be used with single rowfunctions.The GROUP BY clause treats the HAVING clause in the same way as SELECT treatsWHERE.A SELECT statement with a GROUP BY clause cannot have a COLUMN_NAME otherthan the columns available in the GROUP BY list. When GROUP BY is specified, eithereach column in any non-aggregate expression in the select list should be included in theGROUP BY list, or the GROUP BY expression must match exactly the select listexpression.A GROUP BY clause can include an expression as long as it does not include anyagg regate function, and it cannot contain any sub query, either. In SQL Server, GROUPBY “ALL” can be used, but it is optional. When ALL is specified, null values are returned<strong>for</strong> the summary columns of groups that do not meet the search condition.Because <strong>Oracle</strong> and SQL Server SQL are similar, examples are not provided here.Database LinkWhen tables are to be joined across databases that are in different servers, the databaselink functionality can be used. In the examples provided in this section, the databases aredistributed in two geographical locations. One database is in New York, and another is inBos ton. A business user wants to know the total number of orders <strong>for</strong> the month of May,2004.● In <strong>Oracle</strong>, databases are linked using the command CREATE DATABASE LINK.The TNSNAMES.ORA entry <strong>for</strong> the database is required.SELECT COUNT(*)FROM(SELECT ORDERID FROM ORDERMASTERWHERE orderdate > sysdate - 30UNIONSELECT ORDERID FROM ORDERMASTER@BOSTONWHERE ORDERDATE > sysdate - 30);● In SQL Server, some configuration is needed be<strong>for</strong>e accessing remote databases.Be<strong>for</strong>e querying tables from different databases on different servers, log into thefirst database, go to Query Analyzer, and execute the following code.USE MASTERGOEXEC SP_ADDLINKEDSERVER@SERVER= 'BOSTON',@SRVPRODUCT= '',@PROVIDER='SQLOLEDB',@DATASRC='BOSTON\NWIND'GOEXEC SP_ADDLINKEDSRVLOGIN@RMTSRVNAME ='BOSTON',@USESELF='FALSE',@LOCALLOGIN=NULL,

196 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLCASE@RMTUSER ='ABC',@RMTPASSWORD ='ABC'GOExecuting these procedures establishes the link between the servers. Next,execute the following query to retrieve the data from two databases.SELECT COUNT(ORDERID)FROM(SELECT ORDERID FROM ORDERMASTERWHERE ORDERDATE > getdate() - 30UNIONSELECT ORDERID FROM [BOSTON].NWIND.DBO.ORDERMASTERWHERE ORDERDATE > getdate() - 30)CASE is used when there is a need to have "if-else" in this section, a store manager wants to see customer names and segregatelogic. In the example code thatappearsthe orders into the three following categories:● An order value less than $5,000 is small● An order value between $5,000 and $10,000 is medium● An order value greater than $10,000 is largeIn <strong>Oracle</strong>, this task would be accomplished using CASE as shown in the following codeexample:SELECT ORDERID,CASEWHEN SUM(UNITPRICE)

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 197●SQL ServerSELECT COMPANYNAMEFROM [NEWYORK].NWIND.DBO.SUPPLIERSUNIONSELECT COMPANYNAMEFROM [BOSTON].NWIND.DBO.SUPPLIERSSet Operators: IntersectThe intersect operator will only retrieve the common values from more than one table. Inthe following example code, intersect is used to retrieve the supplier names common toboth NEWYORK and BOSTON stores.● <strong>Oracle</strong>●SELECT COMPANYNAME FROM SUPPLIERS@BOSTONINTERSECTSELECT COMPANYNAME FROM SUPPLIERS@NEWYORKclause can be written <strong>for</strong> the sameSet Operators: MinusA minus operator is used when the difference of values from more than one table needsto be fetched. In the following example code, this operator is used to list the suppliernames that are only in the BOSTON database and that are not in NEWYORK database.● <strong>Oracle</strong>●SQL ServerIn SQL Server, a subquery with an EXISTSpurpose.SELECT COMPANYNAME FROM [NEWYORK].NWIND.DBO.SUPPLIERS AWHERE EXISTS(SELECT 'X'FROM [BOSTON].NWIND.DBO.SUPPLIERS BWHERE A.COMPANYNAME = B.COMPANYNAME);SELECT COMPANYNAME FROM SUPPLIERS@BOSTONMINUSSELECT COMPANYNAME FROM SUPPLIERS@NEWYORK;SQL ServerBecause MINUS is not available in SQL Server, NOT EXISTS can be used. Thefollowing example shows how to use the NOT EXISTS operator.SELECT COMPANYNAME FROM SUPPLIERS AWHERE NOT EXISTS(SELECT 'X'FROM [BOSTON].NWIND.DBO.SUPPLIERS BWHERE A.COMPANYNAME = B.COMPANYNAME) ;

198 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLROWNUMROWNUM is a special keyword in <strong>Oracle</strong>. Using ROWNUM can limit the number of rowsretrieved without any condition. In the following example, ROWNUM is used to displaythe top 10 orders from the ORDERDETAILS table.● <strong>Oracle</strong>●SELECT *FROM(SELECT ORDERID, SUM(UNITPRICE)FROM ORDERDETAILSGROUP BY ORDERIDORDER BY SUM(UNITPRICE) DESC)WHERE ROWNUM < 11;SQL ServerSELECT TOP 10 ORDERID, SUM(UNITPRICE)FROM ORDERDETAILSGROUP BY ORDERIDORDER BY SUM(UNITPRICE) DESCData Manipulation Language (DML)DML includes INSERT, UPDATE, and DELETE. The MERGE statement has also beendiscussed. The following sections describe how each command is used in <strong>Oracle</strong> andhow the command can be converted into SQL Server-specific syntax.InsertThe INSERT command is used to add one or more rows to a table. The column valuesare separated by commas. Insert can be used in several different ways within <strong>Oracle</strong>. Allof the different <strong>for</strong>ms are explained under the following headings.Inse rting a row into a table is identical in SQL Server and in <strong>Oracle</strong>. The syntax is shownhere:INSERT INTO TABLE1 VALUES (FIELD1, FIELD2 …);Insert SequencesCompatibility between the <strong>Oracle</strong> tables and the new SQL Server tables should bechecked. If a table in <strong>Oracle</strong> uses SEQUENCES, then SQL Server tables should useIDENTITY.IDENTITY will automatically increment a column value so that no two rows will havesame value <strong>for</strong> the column. To enable this facility, a column can be included in the tablewhich will have its unique value and auto-incrementing defined. This is achieved throughSEQUENCES in <strong>Oracle</strong> and IDENTITY in SQL Server. This column can also be used asprimary key <strong>for</strong> tables that do not have a natural key.A sequence is a database object that can generate unique, sequential integer values. Itcan be used to automatically generate primary key or unique key values. A sequence canbe either in ascending or descending order. The syntax is explained in the followingexamples.● <strong>Oracle</strong>INSERT INTO SUPPLIERS VALUES

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 199●(SUPPLIER_SEQUENCE.NEXTVAL,' Abc Inc.', 'Lingerfelt, Steve', 'Mr.', 'Apt # 104Andrew''s Drive', 'Charlotte', 28262,'USA',7049654371,7049652300);SQL ServerSQL Server has a unique way of handling running serial numbers: the IDENTITYproperty. This property provides a unique incremental value <strong>for</strong> the column. Its usein an insert command is explained later in this section. This is equivalent to<strong>Oracle</strong>'s Sequence. When a column is declared as IDENTITY, a value does nothave to be specified <strong>for</strong> the column. In <strong>Oracle</strong>, the value has to be explicitlyretrieved from a sequence during an insert.The current value of an IDENTITY can be found using the following code:SELECT IDENT_CURRENT ('SUPPLIERS')INSERT INTO SUPPLIERS VALUES(' A bc Inc.', 'Lingerfelt, Steve', 'Mr.', 'Apt # 104 Andrew''s Drive' ,'Charlotte', 28262,'USA','7049654371','7049652300');Using Date Values in Insert OperationsDuring an insert or update, the date <strong>for</strong>mat can be the same as <strong>Oracle</strong> (DD-MON-YYYY).However, while retrieving, the <strong>for</strong>mat will be different. A conversion function that wasdiscussed in the "Functions"section will have to be used. In <strong>Oracle</strong>, to insert the date with time, a conversion of thedate with date time is needed. This is done with the help of the TO_CHAR function. Thisis not required in SQL Server because it already stores the date with time stamp.The following example illustrates how to insert the current date in an insert operation of<strong>Oracle</strong> and SQL Server.● <strong>Oracle</strong>●INSERT INTO OrderMaster VALUES(1,1076,121,SYSDATE,'19-AUG-2004', NULL,'Federal Shipping', 40,'Ernst Handel','2817 Milton Dr.','Dallas','TX','87110')INSERT INTO OrderMaster VALUES(1,1076,121, GETDATE(),'19-AUG-2004', NULL,'Federal Shipping', 40, 'Ernst Handel','2817 MiltonDr.','Dallas','TX','87110')The following example shows how the time part of a date is handled in <strong>Oracle</strong> and howthis can be converted <strong>for</strong> SQL Server database.● <strong>Oracle</strong>●SQL ServerINSERT INTO OrderMaster VALUES(1,1076,121,TO_DATE('01-MAR-2004 13:45:33', 'DD-MON-YYYYHH24:MI:SS'),'19-AUG-2004', NULL, 'Federal Shipping', 40, 'Ernst Handel','2817Milton Dr.',' Dallas','TX','87110')SQL ServerINSERT INTO OrderMaster VALUES(1,1076,121, '01-MAR-2004 13:45:33','19-AUG-2004', NULL, 'Federal Shipping', 40, 'Ernst Handel','2817 MiltonDr.','Dallas','TX' ,'87110')Insert with SubqueryIn many applications, a subquery is used to return a specific subset of rows whichare then inserted into the table. The subquery can refer to any table, view, or

200 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLeven the target table itself. If the subquery returns no rows, then no rows areinserted into the table.UpdateUpdate is an imperative DML statement that facilitates the changes to values of fields inthe tables. In an <strong>Oracle</strong> or SQL Server database, an UPDATE is commonly used toincorporate modifications to an already inserted value. All of the key constraints arehandled by the databases prior to affecting the UPDATE permanently. <strong>Oracle</strong> andSQL Server have followed the conventional ANSI way of using the UPDATE statement.The UPDATE statement can be per<strong>for</strong>med in three different ways:● Simple update. This is a straight<strong>for</strong>ward change to the values of one or morefields of a table, with or without a condition <strong>for</strong> updating.<strong>Oracle</strong> and SQL Server use the same syntax <strong>for</strong> UPDATE statement.● Update with joins. Updates with joins are frequently used when a change isrequired in the field value of only the rows matching specific conditions betweentwo or more tables.<strong>Oracle</strong> and SQL Server use the same syntax <strong>for</strong> UPDATE statement.● Update with subqueries. Requirements will sometimes demand a change to afield value with data from another table. Update with subqueries is useful insituations where data from one table is set to a field from another table.<strong>Oracle</strong> and SQL Server use the same syntax conventions <strong>for</strong> UPDATE withsubqueries. An exception is updates involving correlated subqueries.UPDATE OrderDetails oSET o.unitprice = (SELECT unitpriceFROM Product pWHERE p.productid = o.productid)The preceding <strong>Oracle</strong> update statement can be rewritten using a syntax that isunique to SQL Server as follows:MergeUPDATE oSET o.unitprice = p.unitpriceFROM OrderDetails o JOIN Product pON p.productid = o.productidThis is a new feature in <strong>Oracle</strong> 9i. The MERGE statement is used to update and insertrows in a table. In the following examples, an ORDERPRICE table exists that stores therevised price of a product in a particular order. The price can be revised any number oftimes. If a record already exists, then the price needs to be updated and the datechanged. If a row <strong>for</strong> that order and product does not exist, then you need to insert a newrow with the revised price of the product in that particular order.● <strong>Oracle</strong>MERGE INTO ORDERPRICE AUSING (SELECT ORDERID, PRODUCTID FROM ORDERDETAILS WHERE ORDERID=1AND PRODUCTID =1) BON (A.ORDERID = B.ORDERID AND A.PRODUCTID = B.PRODUCTID)WHEN MATCHED THENUPDATE SET REVISEDPRICE = 120, REVISEDON = SYSDATEWHEN NOT MATCHED THENINSERT INTOORDERPRICE VALUES

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 201●(B.ORDERID, B.PRODUCTID, 100, SYSDATE);SQL ServerTo achieve this functionality in SQL Server, use a stored procedure with thefollowing logic. More in<strong>for</strong>mation about writing stored procedures is included laterin this chap ter in the "Subprograms Conversion" section.declare @orderid char(10)declare @productid char(10)declare @count integerSELECT @count = COUNT(*) FROM ORDERPRICEWHERE ORDERID= @ORDERID AND PRODUCTID = @PRODUCTIDIF @count > 0UPDATE ORDERPRICE SET REVISEDPRICE =120, REVISEDON = GETDATE()WHERE ORDERID = @ORDERID AND PRODUCTID = @PRODUCTIDELSEINSERT INTO ORDERPRICE VALUES(@ORDERID, @PRODUCTID, 100, GETDATE())DeleteAs tables are used, unneeded rows can be removed. DELETE is a DML operation that isused to eliminate all or certain rows from a table, keeping the table structure intact. Eventhough all the rows are deleted, the structure of the table remains and can be populatedwith additional rows using INSERT. By using conditional deletion, only selected rows areeliminated from the table. Conditional deletion is accomplished by using the conventionalWHERE clause. <strong>Oracle</strong> and SQL Server both allow <strong>for</strong> conditional deletion. The ANSIway of writing the DELETE statement is used in both <strong>Oracle</strong> and SQL Server.The following types of delete exist:● Simple delete. A general way of deleting all or selected rows from a table. Asimple delete operation is similar <strong>for</strong> <strong>Oracle</strong> and SQL Server.● Delete all rows. Both <strong>Oracle</strong> and SQL Server offer the TRUNCATE TABLEstatement.● Delete with subqueries. Using subqueries in conjunction with the DELETEoperation allows <strong>for</strong> more specificity. The subquery enables the value <strong>for</strong> theWHERE condition to be fetched from a different table.<strong>Oracle</strong> and SQL Server use the same methodology to delete the rows in a table.● Delete duplicate records. It is possible to have exact copies of rows in a tablethat does not en<strong>for</strong>ce a strict key structure. These situations demand the deletionof all the duplicate records from the table. <strong>Oracle</strong> and SQL Server have differentways to do this:●<strong>Oracle</strong>DELETE FROM TABLE1 WHERE TABLE1.ROWID >(SELECT MIN (TABLE2.ROWID) FROM TABLE2WHERE TABLE1.FIELD1 = TABLE2.FIELD1)● SQL ServerFor an example of how to per<strong>for</strong>m this in SQL Server, refer tohttp://support.microsoft.com/default.aspx?scid=kb;en-us;139444• TruncateBoth <strong>Oracle</strong> and SQL Server offer the TRUNCATE command <strong>for</strong> deleting all rowsof a table with minimal logging.

202 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLStep 2: Transaction ManagementAfter identifying all instances of SQL, transactions need to be carefully modified as part ofthe data migration process. This section discusses how to handle the transactions inSQL Server.To begin, identify all of the transaction commands currently used with <strong>Oracle</strong> andimplement them <strong>for</strong> SQL Server. In <strong>Oracle</strong>, all commands inside two transaction controllanguage statements are considered as a batch. If a set of statements needs to beconsidered as a batch, then all the statements must be inside BEGIN TRANSACTIONand COMMIT TRANSACTION commands. A discussion of these architecture topics isprovided in Appendix A: SQL Server <strong>for</strong> <strong>Oracle</strong> Professionals.Transaction Control Language (TCL)A tr ansaction can be defined as a group of statements that must either succeed or fail asa group. In <strong>Oracle</strong>, transactions are normally implicit in nature and can be explicitlyspecified by use of BEGIN and END clauses. In SQL Server, BEGIN TRAN and ENDTRAN have to be explicitly used to demarcate a transaction.Transaction is controlled by any one of these commands:● COMMIT● ROLLBACK● SAVEPOINTThese commands are discussed in detail under the following headings.COMMITThe COMMIT command is used to end a transaction. Changes are made permanent inthe database with the COMMIT command. This erases all the savepoints inside thetran saction and also releases the locks.After a transaction is committed, the change is permanent and cannot be reverted. Ofcourse, you can always delete the inserted row. There is no way to undo a committedtransaction.The syntax is as follows:● <strong>Oracle</strong>●COMMIT;SQL ServerCOMMIT TRANSACTION ;The COMMIT WORK command functions in the same way as COMMIT TRANSACTION,except COMMIT TRANSACTION accepts a user-defined transaction name. ThisCOMMIT syntax, with or without specifying the optional keyword WORK, is compatiblewith SQL-92. This command is available in SQL Server using the following command:COMMIT WORK;SAVEPOINTA savepoint is a marker that divides a very lengthy transaction into several smaller ones.SAVEPOINT is used to identify a rollback point in the transaction. Thus, SAVEPOINT isused in conjunction with ROLLBACK to revert a portion of current transaction. The syntaxin <strong>Oracle</strong> and SQL Server differs:● <strong>Oracle</strong>

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 203●SAVEPOINT ;SQL ServerSAVE TRANSACTION ;ROLLBACKThe ROLLBACK command is used to undo a portion of the current transaction. It ispossible to roll back the entire transaction so that all changes made by SQL statementsare undone, or to roll back a transaction to a save point so that the SQL statements afterthe save point are rolled back. The syntax in <strong>Oracle</strong> and SQL Server differs:●●<strong>Oracle</strong>ROLLBACK;ROLLBACK TO ;SQL ServerROLLBACK TRANSACTION ROLLBACK TRANSACTION In addition, the ROLLBACK WORK statement function is similar to the ROLLBACK. Theonly difference is that ROLLBACK TRANSACTION accepts a user-defined transactionname. With or without specifying the optional WORK keyword, this ROLLBACK syntax isSQL-92-compatible and is available in SQL Server using the following syntax:ROLLBACK WORKSte p 3: Fetch StrategyCursors are effective <strong>for</strong> row processing and batch processing. <strong>Oracle</strong>-based applicationscan use many c ursors <strong>for</strong> row processing. Analyze the code to determine if it can beconverted without using cursors. Cursor operations are always costly when compared toSET operations because they use temporary memory area and processes. If the cursorsare not handled properly, it may result in dead processes and locks.In <strong>Oracle</strong>, a cursor is defined as a work area to execute the SQL statements and to storeprocessing in<strong>for</strong>mation. <strong>Oracle</strong> creates a work area to process all the SQL statements.That work area is called an implicit cursor. <strong>Oracle</strong> also allows you to define an explicitcursor to process and apply business logic.<strong>Oracle</strong> has implemented the following types of cursors:● Implicit cursors● Explicit cursorsImplicit cursors are opened automatically whenever queries or DML are issued in <strong>Oracle</strong>.SQL Server calls this a default result set.<strong>Oracle</strong> allows defining a cursor with the help of keyword "cursor." Such explicitly declaredcurs ors have a SELECT statement. The output of the select is stored in separate memoryareas and it can be used in a PL/SQL program. Explicit cursors can be parameterized.Transact SQL Cursors, in SQL Server, are based on the DECLARE CURSOR syntax andare used mainly in Transact-SQL scripts, stored procedures, and triggers. Transact-SQLcursors are implemented on the server and are managed by Transact-SQL statementssent from the client to the server.Using Transact-SQL CursorsHigh-level steps <strong>for</strong> using Transact-SQL cursors inside the code include:

204 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL1. Declare Transact-SQL variables to contain the data returned by the cursor. Declareone variable <strong>for</strong> each result set column. Declare the variables to be large enoughto hold the values returned by the column.2. Associate a Transact-SQL cursor with a SELECT statement using the DECLARECURSOR statement. The DECLARE CURSOR statement also defines thecharacteristics of the cursor, such as the cursor name and whether the cursor isread-only or <strong>for</strong>ward-only.3. Use the OPEN statement to execute the SELECT statement and populate thecursor.4. Use the FETCH INTO statement to fetch individual rows and have the data <strong>for</strong>each column moved into a specified variable. Other Transact-SQL statements canthen reference those variables to access the fetched data values. Transact-SQLcursors do not support fetching blocks of rows.5. When you are finished with the cursor, use the CLOSE statement. Closing a cursorfrees some resources, such as the cursor's result set and its locks on the currentrow, but the cursor structure is still available <strong>for</strong> processing if you reissue an OPENstatement. Because the cursor is still present, you cannot reuse the cursor name atthis point. The DEALLOCATE statement completely frees all resources allocated tothe cursor, including the cursor name. After a cursor is de-allocated, you mustissue a DECLARE statement to rebuild the cursor.Th e cursor syntax differs between <strong>Oracle</strong> and SQL Server:● <strong>Oracle</strong>●DECLARECURSOR IS < SELECT STATEMENT>BEGINFOR IN CURSOR_NAMELOOP-- Business LogicEND LOOP;END;SQL ServerDECLARE DECLARE CURSOR FOR BEGINOPEN FETCH NEXT FROM INTO WHILE @@FETCH_STATUS = 0BEGIN-- business logic goes hereFETCH NEXT FROM INTO ENDCLOSE DEALLOCATE END<strong>Oracle</strong> allows the entire cursor record to be transferred into a user-defined data structuredefined using ROWTYPE. In SQL Server, the record values need to be assigned into anindividual variable. The following example uses ROWTYPE to process the SHIPPERStable record byrecord.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 205●●<strong>Oracle</strong>DECLARECURSOR SHIPPER_CURSOR IS SELECT * FROM SHIPPERS;SHIPPER_REC SHIPPERS%ROWTYPE;BEGINOPEN SHIPPER_CURSOR;LOOPFETCH SHIPPER_CURSOR INTO SHIPPER_REC;EXIT WHEN SHIPPER_CURSOR%NOTFOUND;DBMS_OUTPUT.PUT_LINE('SHIPPER NAME IS '||SHIPPER_REC.COMPANYNAME);DBMS_OUTPUT.PUT_LINE('SHIPPER PHONE IS '||SHIPPER_REC. PHONE);END LOOP;CLOSE SHIPPER_CURSOR;END;SQL ServerDECLARE @SHIPPER_NAME VARCHAR(50),@PHONE VARCHAR(50)DECLARE SHIPPER_CURSOR CURSOR FOR SELECT COMPANYNAME,PHONE FROM SHIPPERS;BEGINOPEN SHIPPER_CURSOR;FETCH NEXT FROM SHIPPER_CURSOR INTO @SHIPPER_NAME, @PHONEWHILE @@FETCH_STATUS = 0BEGINPRINT 'SHIPPER NAME IS ' + @SHIPPERNAMEPRINT 'SHIPPER PHONE IS ' + @PHONEFETCH NEXT FROM SHIPPER_CURSOR INTO @SHIPPER_NAME, @PHONEENDCLOSE SHIPPER_CURSORDEALLOCATE SHIPPER_ CURSORENDTransact SQL ExtensionsSQL Server extends the following functionality with cursors. Some of the key featuresinclude:●●●●●●FETCH FIRSTFetches the first row in the cursor.FETCH NEXTFetches the row after the last row fetched.FETCH PRIORFetches the row be<strong>for</strong>e the last row fetched.FETCH LASTFetches the last row in the cursor.FETCH ABSOLUTE nFetches the nth row from the first row in the cursor if n is a positive integer. If n is anegative integer, the row n rows be<strong>for</strong>e the end of the cursor is fetched. If n is 0, norows are fetched.FETCH RELATIVE nFetches the nth row from the current position of the cursor. If n is positive, the nthrow afterthe last row fetched is fetched. If n is negative, the nth row be<strong>for</strong>e the last

206 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLrow fetched is fetched. If n is 0, the same row is fetched again. It also allowsretrieving one row or block of rows from the current position in the result set.It supports data modifications to the rows at the current position in the result set.Step 4: Subprograms ConversionThe next step is to migrate the procedures, functions, and triggers. This sectiondiscusses how each component can be converted <strong>for</strong> use with SQL Server.<strong>Migrating</strong> ProceduresA stored procedure is a precompiled object. This means that a procedure is compiledbe<strong>for</strong>ehand and is readily available <strong>for</strong> the various applications to execute. As a result,time is not wasted parsing and compiling the procedure again. However, the procedurewill be compiled every time if it contains dynamic SQL. Stored procedures in SQL Serverare very similar to procedures in <strong>Oracle</strong> PL/SQL. Some similarities include:● Both can accept parameters and return multiple values in the <strong>for</strong>m of outputparameters (OUT parameter) to the calling procedure.● Both contain programming statements that per<strong>for</strong>m operations in the database,including calling other procedures.● Both can overwrite existing procedures. <strong>Oracle</strong> uses the keyword REPLACE, whileSQL Server uses ALTER.The syntax between <strong>Oracle</strong> and SQL Server procedures differs. The differences areshown in the following examples:● <strong>Oracle</strong>●CREATE OR REPLACE PROCEDURE (PARAMETER1 DATATYPE [IN OUT],PARAMETER2 DATATYPE [IN OUT],)ISVARIABLE1 DATATYPE;VARIABLE2 DATATYPE;BEGINEXECUTABLE STATEMENTS;EXCEPTIONEXECUTABLE STATEMENTS;END;SQL ServerCREATE PROCEDURE [ ; number ][ { @PARAMETER DATATYPE }[ VARYING ] [ = default ] [ OUTPUT ]] [ ,...n ] ASEXECUTABLE STATEMENTSIn the following example, a stored procedure calculates the number of months remaininguntil retirement <strong>for</strong> each employee. Retirement age is passed as a parameter to theprocedure. The output needs to be written into a table named RETIRE. The RETIREtable has two columns. The columns are EMPLOYEEID and MONTHS_REMAINING.The number of months remaining is calculated and inserted into this table. Be<strong>for</strong>e startingthe operation, the table needs to be flushed.● <strong>Oracle</strong>

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 207CREATE OR REPLACE PROCEDURE CALCULATE_RETIRE_MONTHS(RETIRE_AGE NUMBER) ISCURRENT_AGE NUMBER;MONTHS_REMAINING NUMBER;CURSOR EMP_CURSOR IS SELECT EMPLOYEEID, BIRTHDATE FROM EMPLOYEE;BEGINEXECUTE IMMEDIATE 'TRUNCATE TABLE RETIRE';FOR CUR_VAL IN EMP_CURSORLOOPCURRENT_AGE := ROUND(ROUND(SYSDATE - CUR_VAL.BIRTHDATE)/30)MONTHS_REMAINING := (RETIRE_AGE * 12) - CURRENT_AGE;INSERT INTO RETIRE VALUES(CUR_VAL.EMPLOYEE_ID,MONTHS_REMAINING);END LOOP;COMMIT;END;● SQL S erverIF EXISTS (SELECT NAME FROM SYSOBJECTSWHERE NAME = 'CALCULATE_RETIRE_YRS' AND TYPE = 'P')DROP PROCEDURE CALCULATE_RETIRE_YRSGOCREATE PROCEDURE CALCULATE_RETIRE_YRS @RETIRE_AGE INTEGER ASDECLARE @CUR_AGE INTEGER,@MONTHS_REMAINING INTEGERDECLARE @V_DOB DATETIME,@V_EMPLOYEEID VARCHAR(30)DECLARE EMP_CURSOR CURSOR FORSELECT EMPLOYEEID,BIRTHDATE FROM EMPLOYEEBEGINTRUNCATE TABLE RETIRE;OPEN EMP_CURSORFETCH NEXT FROM EMP_CURSOR INTO @V_EMPLOYEEID,@V_DOBIF @@FETCH_STATUS 0BEGINPRINT 'NO EMP'ENDELSEBEGINWHILE (@@FETCH_STATUS = 0)BEGINSET @CUR_AGE = ( SELECT DATEDIFF(MONTH,@V_DOB,GETDATE()) )SET @MONTHS_REMAINING = (SELECT (@RETIRE_AGE * 12) -@CUR_AGE)INSERT INTO RETIRE VALUES(@V_EMPLOYEEID,@MONTHS_REMAINING)FETCH NEXT FROM EMP_CURSOR INTO @V_EMPLOYEEID,@V_DOBENDENDCLOSE EMP_CURSORDEALLOCATE EMP_CURSOREND

208 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLFunctionsWhile si milar to procedures, functions return a value. There may be some mathematicalcalculation needed <strong>for</strong> the application that is readily available in the database server. Ifyou need the result of a complex algorithm as part of a SQL statement, you need to writea functio n that per<strong>for</strong>ms the required calculation and returns a value.The syntax between <strong>Oracle</strong> and SQL Server functions differs, as shown in the followingexamples:● <strong>Oracle</strong>●CREATE OR REPLACE FUNCTION (PARAMETER DATATYPE,PARAMETER DATATYPE ETC ..) RETURN DATATYPEISBEGINRETURN EXCEPTION;END;SQL ServerCREATE FUNCTION @PARAMETER DATATYPE,@PARAMETER DATATYPE ETC ..RETURNS ASBEGINRETURN ENDThe difference between built-in functions in <strong>Oracle</strong> and SQL Server are discussed here.<strong>Oracle</strong> also has a function called NEXT_DAY that returns the date of the first weekdaynamed by char that is later than the current date. The char argument must be a day ofthe week in the date language of the session, either the full name or the abbreviation.The minimum number of letters required is the number of letters in the abbreviatedversion. Any characters immediately following the valid abbreviation are ignored and thereturn value has the same hours, minutes, and seconds component as the argumentdate.By default, this function is not available in SQL Server. But the following example showsone way to provide this function in SQL Server, and it can be expanded to meet yourneeds:CREATE FUNCTION NEXT_DAY(@D DATETIME,@DAY VARCHAR(10)) RETURNS DATETIME ASBEGINDECLARE @DAY_NUMBER INTEGERDECLARE @NEWDATE DATETIMEIF UPPER(@DAY)='SUNDAY'BEGINIF ( 1 - DATEPART(DW,@D))=0SET @NEWDATE = @D + 7ELSE IF ( 1 - DATEPART(DW,@D)) < 0SET @NEWDATE = @D + 1 + ( 7 - DATEPART(DW,@D))ELSE

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 209ENDSET @NEWDATE = @ D + 1 - DATEPART(DW,@D)ELSE IF UPPER(@DAY)='MONDAY' OR UPPER(@DAY)= ‘MON’BEGINIF ( 2 - DATEPART(DW,@D)) = 0SET @NEWDATE = @D + 7ELSE IF ( 2 - DATEPART(DW,@D))< 0SET @NEWDATE = @D + 2 + ( 7 - DATEPART(DW,@D))ELSESET @NEWDATE = @D + 2 - DATEPART(DW,@D)ENDELSE IF UPPER(@DAY)='TUESDAY' OR UPPER(@DAY)= ‘TUE’BEGINIF ( 3 - DATEPART(DW,@D)) = 0SET @NEWDATE = @D + 7ELSE IF ( 3 - DATEPART(DW,@D))< 0SET @NEWDATE = @D + 3 + ( 7 - DATEPART(DW,@D))ELSESET @NEWDATE = @D + 3 - DATEPART(DW,@D)ENDELSE IF UPPER(@DAY)='WEDNESDAY' OR UPPER(@DAY)= ‘WED’BEGINIF ( 4 - DATEPART(DW,@D)) = 0SET @NEWDATE = @D + 7ELSE IF ( 4 - DATEPART(DW,@D))< 0SET @NEWDATE = @D + 4 + ( 7 - DATEPART(DW,@D))ELSESET @NEWDATE = @D + 4 - DATEPART(DW,@D)ENDELSE IF UPPER(@DAY)='THURSDAY' OR UPPER(@DAY)= ‘THU’BEGINIF ( 5 - DATEPART(DW,@D)) = 0SET @NEWDATE = @D + 7ELSE IF ( 5 - DATEPART(DW, @D))< 0SET @NEWDATE = @D + 5 + ( 7 - DATEPART(DW,@D))ELSESET @NEWDATE = @D + 5 - DATEPART(DW,@D)ENDELSE IF UPPER(@DAY)='FRIDAY' OR UPPER(@DAY)= ‘FRI’BEGINIF ( 6 - DATEPART(DW,@D)) = 0SET @NEWDATE = @D + 7ELSE IF ( 6 - DATEPART(DW,@D))< 0SET @NEWDATE = @D + 6 + ( 7 - DATEPART(DW,@D))ELSESET @NEWDATE = @D + 6 - DATEPART(DW,@D)ENDELSE IF UPPER(@DAY)='SATURDAY' OR UPPER(@DAY)= ‘SAT’BEGINIF ( 7 - DATEPART(DW,@D)) = 0

210 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLSET @NEWDATE = @D + 7ELSE IF ( 7 - DATEPART(DW,@D))< 0SET @NEWDATE = @D + 7 + ( 7 - DATEPART(DW,@D))ELSESET @NEWDATE = @D + 7 - DATEPART(DW,@D)ENDELSESET @NEWDATE = NULLRETURN @NEWDATEENDTriggers<strong>Oracle</strong> and SQL Server provide two primary mechanisms <strong>for</strong> en<strong>for</strong>cing business rulesand data integrity through constraints and triggers. A trigger is a special type of storedprocedure that automatically takes effect when an event occurs. The event can beINSERT, UPDATE, or DELETE. The trigger and the statement that triggers are treated asa single transaction, which can be rolled back from within the trigger. If an error isdetected, the entire transaction is automatically rolled back.<strong>Oracle</strong> uses two types of triggers on tables: table-level triggers and row-level triggers. Ifthe key word FOR EACH ROW is specified, then it is a row-level trigger. Row-leveltriggers are fired <strong>for</strong> each row when it is affected. For example, if an update statementchanges 5 rows, then the trigger will be fired 5 times. Table-level triggers are only firedonce. In a table-level trigger, individual values cannot be captured. Row-level triggerscapture the individual rows with the help of the keywords :NEW and :OLD. Unlike <strong>Oracle</strong>,SQL Server does not have two types of triggers. The individual values can be capturedfrom a special table called INSERTED. Old values can be fetched from the DELETEDtable and the new changed values can be retrieved from the INSERTED table.The deleted values can be referred with the special variable :OLD in <strong>Oracle</strong>. SQL Serverhas a special table called DELETED. The DELETED table stores copies of the affectedrows during DELETE and UPDATE statements. During the execution of a DELETE orUPDATE statement, rows are deleted from the trigger table and transferred to theDELETED table. The DELETED and INSERTED tables in SQL Server are onlyconceptual; they do not physically exist.A mapping of the functionality of triggers in <strong>Oracle</strong> and SQL Server as well as acomparison of the syntax is available under the topic "Triggers" in Chapter 6:"Developing: Databases — <strong>Migrating</strong> Schemas."The syntax <strong>for</strong> the triggers differs as follows:● <strong>Oracle</strong> triggersSeparate syntax is used <strong>for</strong> each trigger command:● INSERT trigger syntaxCREATE OR REPLACE TRIGGER [ BEFORE | AFTER ] INSERT ON [ FOR EACH ROW ]DECLAREBEGINEXCEPTIONEND;

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 211●UPDATE trigger syntaxCREATE OR REPLACE TRIGGER [ BEFORE | AFTER ] UPDATE OF ON [ FOR EACH ROW ]DECLAREBEGINEXCEPTION●END;DELETE trigger syntaxCREATE OR REPLACE TRIGGER [ BEFORE | AFTER ] DELETE ON [ FOR EACH ROW ]DECLAREBEGINEXCEPTIONEND;●SQL ServerUnlike <strong>Oracle</strong>, only one syntax is needed <strong>for</strong> trigger functions in SQL Server:CREATE TRIGGER ON {FOR|AFTER|INSTEAD OF}{[INSERT][,][UPDATE][,][DELETE]}AS[{IF UPDATE(column)[{AND|OR}UPDATE(column)]}]EXECUTABLE STATEMENTSThe following example further illustrates the use of trigger functions. In this example, thePRODUCT tables need to be updated when an order is issued against any product. Thefollowing code uses an INSERT trigger to per<strong>for</strong>m this task.● <strong>Oracle</strong>●CREATE TRIGGER UPDATE_STOCKAFTER INSERT ON ORDERDETAILSFOR EACH ROWBEGINUPDATE PRODUCT SET UNITINSTOCK = UNITINSTOCK - :NEW.QUANTITYWHERE PRODUCTID = :NEW.PRODUCTID;EXCEPTIONWHEN OTHERS THENNULL;END;SQL ServerCREATE TRIGGER UPDATE_STOCK ON ORDERDETAILSAFTER INSERT ASBEGINUPDATE PRODUCT SET UNITINSTOCK = UNITINSTOCK – QUANTITY

212 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLFROM INSERTED WHERE PRODUCT.PRODUCTID = INSERTED.PRODUCTIDENDINSTEAD OF TriggersIn gene ral, complex views are not updateable. Complex views are defined as normalviews that include more than one table or have GROUP BY expressions. Complex viewscan b e updated using INSTEAD OF triggers. Both SQL Server and <strong>Oracle</strong> have theoption of INSTEAD OF triggers. The INSTEAD OF trigger is generally defined on theview instead of on a table. In <strong>Oracle</strong>, INSTEAD OF triggers can be applied only to theview and not to tables. In SQL Server, INSTEAD OF triggers can be applied to views andtables. When an insert, update or delete statement is executed against the table, theINSTEAD OF trigger is executed in place of the triggering statement.Also, INSTEAD OF triggers are executed instead of the triggering action. These triggersare executed after the inserted and deleted tables are created, but be<strong>for</strong>e any otheractions are taken. They are executed be<strong>for</strong>e any constraints, so they can per<strong>for</strong>mpreprocessing that supplements the constraint action.The triggering mechanism on INSTEAD OF triggers is implemented such that the triggeris not called recursively. The statement is processed as if there is no INSTEAD OFtrigger defined <strong>for</strong> the table.If an UPDATE statement is executed on a view that has an INSTEAD OF trigger, thetrigger will be called, but it is not executed recursively. The UPDATE statement isresolved against the base tables underlying the view. In this case, the view definitionmust meet all of the restrictions <strong>for</strong> an updateable view. The UPDATE executed by thetrigger is processed against the view as if the view did not have an INSTEAD OF trigger.The columns changed by the UPDATE must be resolved to a single base table. Eachmodification to underlying base tables starts the chain of applying constraints and firingAFTER triggers defined <strong>for</strong> the table.SQL Server provides most of the functionality present in <strong>Oracle</strong> with respect to triggerswith very little differences in their implementation. SQL Server, however, does not havethe BEFORE triggers and can be programmed using the INSTEAD OF triggers on tables.In SQL Server triggers on views have the same kind of features as seen on triggers ontables as shown by the following syntax:CREATE TRIGGER ON {FOR|AFTER|INSTEAD OF}{[INSERT][,][UPDATE][,][DELETE]}ASBEGIN[{IF UPDATE(column)[{AND|OR}UPDATE(column)]EXECUTABLE STATEMENTSENDAn example of the use of INSTEAD OF triggers on view is given in:http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vdbt7/html/dvconusinginsteadoftriggersonviews.asp.Error HandlingRun-time errors in <strong>Oracle</strong>'s PL/SQL programs are done through exceptions andexception handlers. Exceptions are raised when errors occur. Although there are predefinedsystem errors, users can also define their own errors in the declaration sectionusing the syntax:exception_nameEXCEPTION;

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 213The user-defined exceptions can be triggered using the syntax:RAISE exception_name;Each BEGIN … END block has an associatedend whose syntax is as follows.EXCEPTION WHEN exception_name THEN… statements …END;exception handler section defined at theAlthough these exception handler sections are absent in SQL Server at the block level,error handling is per<strong>for</strong>med through the use of the global variable @@Error, which ispassed to the calling program and can be handled there. SQL Server sets the value ofthe @@Error variable after each TSQL statement. For example:,INSERT ….IF @@Error 0BEGINENDSELECT 'Unexpected error occurred: Insert failed', @@ErrorReturn @@Error<strong>Oracle</strong> has many predefined exceptions, such as NO_DATA_FOUND,TOO_MANY_ROWS, ZERO_DIVIDE, INVALID_CURSOR, etc. The predefined exceptionOTHERS is of special interest because it can be used as a catch-all exception <strong>for</strong> anyexceptions <strong>for</strong> which there is no definition in the exception section.SQL Server error messages can be viewed by selecting sysmessages system table.Each SQL Server internal error is qualified into various severity levels. The severity oferrors ranges from 1 to 25. Errors with severity 19 and above are considered critical andmay result in complete abortion of the batch. In such cases, @@ Error may not capturetheerror raised.Similar in functionality to user-defined exceptions and theRAISE_APPLICATON_ERROR function in <strong>Oracle</strong>, SQL Server provides ways to createcustomized error messages that can be raised within TSQL code. These are called user-defined errors and can be raised using RAISERROR statement. If you are referencing anerror number in the RAISERROR function in TSQL, you must create the user-definedmessage. You can also dynamically specify a text message in the RAISERROR function.This is done by using sp_addmessage system stored procedure. For more in<strong>for</strong>mationon howto create and raise user-defined errors, seehttp:/ /msdn.microsoft.com/library/defa ult.asp?url= /library/enus/acdata/ac_8_con_05_3f76.asp.Step 5: Job Scheduling<strong>Oracle</strong> uses application code and OS utilities to schedule a job. SQL Server usesSQL Server agent to per<strong>for</strong>m these jobs. The in<strong>for</strong>mation in this section describescreating a job and scheduling it in SQL Server.Scheduling Functions and JobsSome frequently used scheduling functions that are packaged with <strong>Oracle</strong> are discussedin this section. They include:● DBMS_JOB. This is an <strong>Oracle</strong> supplied package <strong>for</strong> scheduling jobs. Severaldifferent procedures are packed inside this package.Included are:

214 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL●●●●DBMS_JOB.INSTANCE. This procedure is used to assign a particular instanceto execute a jobDBMS_JOB.CHANGE. This is used to alter the schedule of a job.DBMS_JOB.SUBMIT. After the creation of job, this procedure submits a job tothe <strong>Oracle</strong> instance.DBMS_JOB.RUN. Jobs can be executed on demand using this procedure.●cron: cron is a daemon, which means that it only needs to be started once, andwill lay dormant until it is required. Generally, a SQL file is written that calls aparticular procedure. This SQL file is called from a shell script and this script isscheduled using cron. This is how a job is scheduled in <strong>Oracle</strong> running on UNIX.In SQL Server, jobs can be executed in the following ways:● Using the Enterprise Manager● Using the stored procedures SP_ADD_JOB and SP_ADD_JOBSCHEDULEUsing SQL Server Enterprise Manager A job can be scheduled by using the following steps.To execute a job in the background on scheduled basis, SQL Server agent must be running.1. Log in to Enterprise Manager.2. Expand the server group and then expand the server. Expand Management.Expand SQL Server Agent and select the Jobs node.3. Create a new job by right-clicking Jobs.4. Enter a name <strong>for</strong> the job in the Name field.5. Check the Enabled check box to make the job available <strong>for</strong> execution eitherimmediately or by scheduling it. A disabled job runs only if a user explicitlyexecutes it..6. In the Owner list, select a user to be the owner of the job.7. Write the description about the job in Description text area.8. Select the Steps tab. A job step is an action that the job takes on a database or aserver. Every job must have at least one job step. Job steps can be operatingsystem commands, Transact-SQL statements, or ActiveX Scripts.9. Click New to get the job step dialog box. Enter a job step name in the Job stepname box. Select the type in the Type list, For example, you can click Operatingsystem command (CmdExec).10. Enter a value from 0 to 999999 in the Process exit code dialog box.11. Enter the operating system command or executable program in the command box.If you select Transact-SQL statements or ActiveX scripts, you need to specify thecommands as per the selection.12. In the Schedules tab, the schedule can be specified. Jobs can be scheduled to runweekly, daily, or recursive.13. In the Notifications tab, you can specify an e-mail address to send a notification ifa job fails or succeeds. Messages can also be sent to a pager.Using SP_ADD_JOBJobs in SQL Server can also be scheduled using the stored procedure SP_ADD_JOB.This simply adds a job in SQL Agent service. Job steps and scheduling can be done onlywith other procedures. The syntax <strong>for</strong> use and descriptions are provided in the followingexample:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 215SP_ADD_JOB [ @JOB_NAME = ] 'JOB_NAME'[ , [ @ENABLED = ] ENABLED ][ , [ @DESCRIPTION = ] 'DESCRIPTION' ][ , [ @OWNER_LOGIN_NAME = ] 'LOGIN' ][ , [ @NOTIFY_LEVEL_EVENTLOG = ] EVENTLOG_LEVEL ][ , [ @NOTIFY_LEVEL_EMAIL = ] EMAIL_LEVEL ][ , [ @NOTIFY_LEVEL_NETSEND = ] NETSEND_LEVEL ][ , [ @NOTIFY_LEVEL_PAGE = ] PAGE_LEVEL ][ , [ @NOTIFY_EMAIL_OPERATOR_NAME = ] 'EMAIL_NAME' ][ , [ @NOTIFY_NETSEND_ OPERATOR_NAME = ] 'NETSEND_NAME' ][ , [ @NOTIFY_PAGE_OPERATOR_NAME = ] 'PAGE_NAME' ][ , [ @DELETE_LEVEL = ] DELETE_LEVEL ][ @JOB_NAME = ] 'JOB_NAME'@JOB_ NAME is the name of the job. The name must be unique and cannot contain thepercent (%) character. The commonly used parameters include:● [ @ENABLED = ] ENABLED@ENABLED indicates the status of the added job. ENABLED has a default of 1(enabled). If 0, the job is not enabled and does not run according to its schedule,but it can be run manually.● [ @DESCRIPTION = ] 'DESCRIPTION'@DESCRI PTION is the description of the job. This description can be a maximumof 512 characters.● [ @OWNER_LOGIN_NAME = ] 'LOGIN'@OWNER_LOGIN_NAME is the name of the login that owns the job.● [ @ NOTIFY_LEVEL_EVENTLOG = ] EVENTLOG_LEVEL@NOTIFY_LEVEL_EVENTLOG is a value indicating when to place an entry in theWindows® application log (Event viewer) <strong>for</strong> this job. The value can contain one ofthe values described in Table 11.18:Table 11.18: Values <strong>for</strong> EVENTLOG_LEVEL <strong>for</strong> SP_ADD_JOBValueDescription0 Never1 On success2 (default) On failure3 Always●●●●[ @NOTIFY_LEVEL_EMAIL = ] EMAIL_LEVELThe value indicates when to send e-mail upon the completion of this job. This usesthe same values as listed in Table 11.18.[ @NOTIFY_LEVEL_NETSEND = ] NETSEND_LEVELThe value indicates when to send a network message upon the completion of thisjob. This uses the same values as listed in Table 11.18.[ @NOTIFY_LEVEL_PAGE = ] PAGE_LEVELThe value indicates when to send a page upon the completion of this job. Thisuses the same values as listed in Table 11.18.[ @NOTIFY_EMAIL_OPERATOR_NAME = ] 'EMAIL_NAME'

216 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL●●●This is the e-mail address of the person to send e-mail to when EMAIL_LEVEL isreached.[ @NOTIFY_NETSEND_OPERATOR_NAME = ] 'NETSEND_NAME'Name of the operator to whom the network message is sent upon completion ofthis job.[ @NOTIFY_PAGE_OPERATOR_NAME = ] 'PAGE_NAME'Name of the person to page upon completion of this job.[ @DELETE_LEVEL = ] DELETE_LEVELThis value indicates when to delete the job. This uses the same values as listed inTable 11.18.The following example shows how to create a job from the stored procedure. This createsa job named FILE2. The job is enabled with the notification level of zero. No notificationswill be created upon success or failure. Operator DBO is assigned as owner <strong>for</strong> this job.USE MSDBEXEC SP_ADD_JOB @JOB_NAME = 'FILE2',@ENABLED = 1,@DESCRIPTION = 'FILE DUMP JOB',@OWNER_LOGIN_NAME = 'DBO',@NOTIFY_LEVEL_EVENTLOG = 0,@NOTIFY_LEVEL_EMAIL = 0,@NOTIFY_LEVEL_NETSEND = 0,@NOTIFY_LEVEL_PAGE = 0,@DELETE_LEVEL = 0After the job is created, it must have some steps to execute. The steps define thefunction of the job. The following example runs a Data Trans<strong>for</strong>mation package by usingthe DTSRUN utility. SUBSYSTEM should be CMDEXEC to run any utility from a job.USE MSDBEXEC SP_ADD_JOBSTEP @JOB_NAME = 'FILE2',@STEP_NAME = 'STEP1 IN FILE2',@SUBSYSTEM = 'CMDEXEC',@COMMAND = 'DTSRUN /S "(LOCAL)" /N "FILETRANSFER" /U "SA" /P "SA" ',@RETRY_ATTEMPTS = 5,@RETRY_INTERVAL = 5@SUBSYSTEM is used by the SQL Server agent service. The available values aredescribed in Table 11.19.Table 11.19: Values <strong>for</strong> @SUBSYSTEM <strong>for</strong> SP_ADD_JOBSubsystem TypeACTIVESCRIPTINGCMDEXECDISTRIBUTIONSNAPSHOTLOGREADERMERGE'TSQL' (default)DescriptionActive ScriptOperating-system command or executable programReplication Distribution Agent jobReplication Snapshot Agent jobReplication Log Reader Agent jobReplication Merge Agent jobTransact-SQL statement@COMMANDis the actual command to execute. In the following example, the DTSRUNutility is used. Any executable can be called using @COMMAND.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 217Any number of steps can be added to a single job. The sequence of the steps isdetermined by the parameter @STEP_ID in this procedure.After the steps have been created, the job can be either executed manually or scheduled.If it needs to be scheduled, then SP_ADD_JOBSCHEDULE is used with a set ofparameters.This example highlights how to schedule a job FILE2 to occur everyday at 1:00 A.M. inSQL Server.USE MSDBEXEC SP_ADD_JOBSCHEDULE @JOB_NAME = 'FILE2',@NAME = 'DAILY LOAD',@FREQ_TYPE = 4, -- DAILY@FREQ_INTERVAL = 1,@ACTIVE_START_TIME = 10000@FREQ_TYPE is the frequency type. It can accept any one of the values listed in Table11.20:Table 11.20: Values <strong>for</strong> @FREQ_TYPE <strong>for</strong> SP_ADD_JOBValue Description1 Once4 Daily8 Weekly16 Monthly32 Monthly, relative to freq interval64 Run when SQL Server Agent service starts128 Run when the computer is idle@FREQ_INTERVAL acts depend upon the value of @FREQ_TYPE. For example, if@ FREQ_TYPE is set as once, then @ FREQ_INTERVAL has no impact. If@FREQ_INTERVAL is set to run weekly, then @FREQ_INTERVAL is used to indicateon which day the job should run.For more in<strong>for</strong>mation on this topic, refer to the MSDN library at http://www.msdn.com.Step 6: Interface File ConversionAny application will have inbound and outbound interface files. During applicationmigration, it is the application developer's responsibility to consider all inbound as well asoutbound files. External applications will use specified <strong>for</strong>mats. Even after the conversionfrom <strong>Oracle</strong>, the external application will still need the interface file in the same <strong>for</strong>mat.Similarly, the external application might send some interface files to the database.Considering that the <strong>for</strong>mat might remain the same, application code must be convertedin such a way that the application will handle the file, even though it is not in aSQL Server-specific <strong>for</strong>mat.Step 7: Workflow AutomationWhen per<strong>for</strong>ming the application migration, workflow must also be examined. Thissection discusses how to sendmail from the SQL Server database.

218 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQLSending MailSending mail from an application is a very common requirement. <strong>Oracle</strong> includes apackage named UTL_SMTP to provide e-mail functions. Using UTL_SMTP, applicationdevelopers write their code to send notification mails from PL/SQL programs. Somesetup is needed in the server side be<strong>for</strong>e UTL_SMTP can be used.SQL Server has several options to send e-mail. Be<strong>for</strong>e using these options, the mailaccounts and mail service in the server where SQL Server resides needs to be set upand configured. After this is set up, the XP_SENDMAIL stored procedure can be used tosend notification mails. XP_SENDMAIL has all the options of mail services, includingattachments. For example, the error log file can be sent to the administrator in case ofserver side errors. Be<strong>for</strong>e using mail options, set up SQL Mail in SQL Server Enterprise Managerusing the following steps:1. Expand the server group and then expand the server.2. Expand Support Services, right-click SQL Mail, and then click Properties.3. In the Profile list, select the profile that you created earlier.4. Click Test if you want to test the SQL mail. After SQL mail is set up, jobs can be configured to send mail alerts on jobcompletion to indicate whether the job succeeded or failed. To configure thejobs, follow these steps:1. Go to Jobs, select a particular job, and then click Properties.2. On the Notification tab, you can enable the mailing option upon success or failure.3. To send mail from Jobs, the Mail component needs to be started. This can bestarted automatically whenever SQL Server agent starts. Alternatively,XP_STARTMAIL can be used to start the mail agent of SQL Server.In addition, XP_SENDMAIL can be used to send mail from T-SQL batches, triggers, orprocedures. The syntax is shown in the following example:XP_SENDMAIL {[@RECIPIENTS =] 'RECIPIENTS [;...N]'}[,[@MESSAGE =] 'MESSAGE'][,[@QUERY =] 'QUERY'][,[@ATTACHMENTS =] 'ATTACHMENTS [;...N]'][,[@COPY_RECIPIENTS =] 'COPY_RECIPIENTS [;...N]'[,[@BLIND_COPY_RECIPIENTS =] 'BLIND_COPY_RECIPIENTS [;...N]'[,[@SUBJECT =] 'SUBJECT']The following example sends a mail to the mail ID SQLDBA@ABC.COM and a copy toanother mail ID SQLDBA1@ABC.COM. This also sends an attachment with the name"error.log" that is in the directory C:\.XP_SENDMAIL @RECIPIENTS='SQLDBA@ABC.COM', @MESSAGE='Test mail from SQL Mail',@ATTACHMENTS='C:\ERROR_LOG', @COPY_RECIPIENTS='@SQLDBA1@ABC.COM', @SUBJECT='TestSubject'Step 8: Per<strong>for</strong>mance TuningAfter the code changes have been incorporated, the next step is to review and tune theper<strong>for</strong>mance. Make sure proper joins are in place and all possible indexed columns areused while executing the query.General techniques and guidelines are discussed in thissection.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 219After following these optimization techniques, test the application with a test database. Ifpossible, use a copy of production data while testing so that the real response times canbe recorded and more time can be spent tuning the application.The goal of per<strong>for</strong>mance tuning is to minimize the response time <strong>for</strong> each query and tomaximize the throughput of the entire database server by reducing network traffic, diskI/O, and CPU time. This goal is achieved through understanding applicationrequirements, the logical and physical structure of the data, and tradeoffs betweenconflicting uses of the database. Per<strong>for</strong>mance strategies vary in their effectiveness, andsystems with different purposes, such as operational systems and decision supportsystems, require different per<strong>for</strong>mance skills.System per<strong>for</strong>mance is designed and built into a system. It does not just happen.Per<strong>for</strong>mance issues should be considered throughout the development cycle, not just atthe end when the system is implemented. Many per<strong>for</strong>mance issues that result insignificant improvements are achieved by careful design from the outset.Per<strong>for</strong>mance problems are usually the result of competition <strong>for</strong>, or exhaustion of, systemresources.When a system resource is exhausted, the system is unable to scale to higherlevels of per<strong>for</strong>mance. Although other system-level per<strong>for</strong>mance issues, such as memoryor hardware, are certainly candidates <strong>for</strong> study, experience shows that the per<strong>for</strong>mancegains from tuning a query are only incremental when there are fundamental problems inits design.This section describes how SQL Server queries can be optimized when migrating from<strong>Oracle</strong> applications.For example, in <strong>Oracle</strong>, there are several areas where a DBA concentrates on tuning thedatabase and queries, such as:● Memory tuning● I/O tuning● SQL tuning● Managing data and transactionsSQL Server automatically manages available hardware resources, reducing the need <strong>for</strong>extensive system-level manual tuning. Apart from this automatic management,SQL Server provides several ways to optimize per<strong>for</strong>mance during the development andafter the system is released into production. These methods are discussed under thefollowing headings.Query TuningIt may be tempting to address a per<strong>for</strong>mance problem solely by system-level serverper<strong>for</strong>mance tuning; <strong>for</strong> example, by altering memory size, type of file system, andnumber and type of processors. Generally, most per<strong>for</strong>mance problems cannot beresolved this way. They must be addressed by analyzing the application, queries, andupdates that the application is submitting to the database, and how these queries andupdates interact with the database schema.Unexpected long-lasting queries and updates can be caused by:● Slow network communication● Inadequate memory in the server computer● Lack of useful statistics● Out-of-date statistics● Lack of useful indexes

220 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL●●Lack of useful data stripingImproper database designThese issues can be resolved only by looking at the query and its path of execution.SQL Server has several ways to identify all of these issues. Two of the commonly usedmethods, SQL Profiler and the SET SHOWPLAN statement, are discussed here. Refer toAppendix B <strong>for</strong> a list of references about improving per<strong>for</strong>mance.SQL ProfilerThis graphical tool allows system administrators to monitor events in an instance ofSQL Server. Each event can be captured to a file or another table. Using this data, thequery can be analyzed. A stored procedure that hampers the per<strong>for</strong>mance can also bemonitored.Only use the SQL Profiler <strong>for</strong> suspicious events. As SQL Profiler is used, it can slowdown the server and increase the trace file size. Specific events can be filtered so only asubset of data can be monitored.After you have traced the events, SQL Profiler allows captured event data to be replayedagainst an instance of SQL Server, effectively re-executing the saved events as theyoccurred originally.SQL Profiler can be used to:● Monitor the per<strong>for</strong>mance of an instance of SQL Server.● Debug Transact-SQL statements and stored procedures.● Identify slow-executing queries.● Test SQL statements and stored procedures in the Developing Phase of a projectby going through statements to confirm that the code works as expected.● Troubleshoot problems in SQL Server by capturing events on a production systemand replaying them on a test system. This is useful <strong>for</strong> testing or debuggingpurposes and allows users to continue using the production system withoutinterference.● Audit and review activity that occurred on an instance of SQL Server. This allows asecurity administrator to review any of the auditing events, including the successand failure of a login attempt and the success and failure of permissions inaccessing statements and objects.• Provide input to the Index Tuning Wizard to determine index usage suggestions.Using SET SHOWPLAN in SQL ServerSET SHOWLAN is similar to the <strong>Oracle</strong> EXPAIN PLAN command, and it is used todisplay detailed in<strong>for</strong>mation about a query. SET SHOWPLAN_ALL causes SQL Servernot to execute Transact-SQL statements. Instead, SQL Server returns detailedin<strong>for</strong>mation about how the statements are executed and provides estimates of theresource requirements <strong>for</strong> the statements. The syntax <strong>for</strong> this command is:SET SHOWPLAN_ALL {ON | OFF}When SET SHOWPLAN_ALL is ON, SQL Server returns execution in<strong>for</strong>mation <strong>for</strong> eachstatement without executing it, and Transact-SQL statements are not executed. After thisoption is set ON, in<strong>for</strong>mation about all subsequent Transact-SQL statements is returneduntil the option is set OFF.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 221For example, if a CREATE TABLE statement is executed while SET SHOWPLAN_ALL isON, SQL Server returns an error message. When SET SHOWPLAN_ALL is OFF,SQL Server executes the statements without generating a report.Use SET SHOWPLAN_TEXT to return readable output <strong>for</strong> Microsoft MS-DOSapplications, such as the osql utility.SET SHOWPLAN_TEXT and SET SHOWPLAN_ALL cannot be specified inside a storedprocedure; they must be the only statements in a batch.SET SHOWPLAN_ALL returns in<strong>for</strong>mation as a set of rows that <strong>for</strong>m a hierarchical treerepresenting the steps taken by the SQL Server query processor as it executes eachstatement. Each statement reflected in the output contains a single row with the text ofthe statement, followed by several rows with the details of the execution steps.For a more detailed view of the output obtained by turning on SET SHOWPLAN_ALL,refer to http://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_set-set_365o.asp.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 22312Developing: Applications —<strong>Migrating</strong> PerlIntroduction and GoalsThis chapter contains a detailed discussion of changes that must be made to Perlapplications to work with Microsoft® SQL Server. At the conclusion of this chapter, thePerl application should be capable of successfully connecting to the SQL Serverdatabase that was migrated from <strong>Oracle</strong> and the solution can be tested.As discussed in the "Define the <strong>Solution</strong> Concept" section of Chapter 2, "EnvisioningPhase", there are four different strategies available <strong>for</strong> transitioning applications in an<strong>Oracle</strong> to SQL Server migration project. The strategies are:● Interoperate the application with UNIX.● Port or rewrite the application to the Microsoft .NET plat<strong>for</strong>m.● Port or rewrite the application to the Microsoft Win32® plat<strong>for</strong>m.● Quick port using the Windows® Services <strong>for</strong> UNIX 3.5 plat<strong>for</strong>m.Perl is an interpreted scripting language that runs on both UNIX and Windows. Becauseof the cross-plat<strong>for</strong>m capabilities of Perl, some of these strategies are more logical thanothers.For example, because Perl can be ported to Windows, there is no need to rewrite theapplication in the .NET framework or <strong>for</strong> the Win32® environment. Also, because theapplication can run within the Windows environment, a quick port usingWindows Services <strong>for</strong> UNIX is not necessary and would only prevent the application fromtightly integrating with Windows.Based on available migration strategies, two scenarios can be developed to migrate Perlapplications. The solution scenarios are:● Scenario 1: Interoperation of Perl on UNIX with SQL ServerIf the business requirements do not include eliminating the UNIX environment, aninteroperation strategy can be implemented quickly. Few changes need to bemade to the source code, and installing a new driver allows the Perl application toconnect to a SQL Server database. Interoperation can also be used as an interimstep if the migration is per<strong>for</strong>med in phases.● Scenario 2: Port the Perl Application to Win32

224 Developing: Applications — <strong>Migrating</strong> PerlPerl applications can also be ported to run natively on the Windows plat<strong>for</strong>m. Aswith interoperation, few changes need to be made to the source code.Note If your Perl applications use UNIX system calls extensively (such as frequent useof syscall and exec), porting them to Windows Services <strong>for</strong> UNIX/Interix may be asuitable option because Interix has more support <strong>for</strong> the desired system calls. Chapter2, "Envisioning Phase," provides a more detailed discussion of when choosingServices <strong>for</strong> UNIX would be more appropriate when moving to a Windows-basedplat<strong>for</strong>m.You will need the following to implement this option (porting Perl applications to Services<strong>for</strong> UNIX/SQL Server):● A port of Perl <strong>for</strong> Interix (downloadable from Interop Systems athttp://www.interopsystems.com/tools/warehouse.htm), which ships with thenecessary DBI, DBD::ODBC and DBD::Sybase modules.● A connectivity driver to the SQL Server database. This is provided by the port ofFreeTDS on Interix and is downloadable from Interop Systems athttp://www.interopsystems.com/tools/db.htm. FreeTDS provides two connectivityoptions <strong>for</strong> the Perl application to connect to the SQL Server database. One is alibrary called CTlib, which can be accessed through the DBD::Sybase module. Theother is an odbc driver, which can be accessed though the DBD::ODBC module.● If you use the ODBC driver, you will also need an ODBC driver manager. Twodifferent ODBC driver managers iODBC and unixODBC are available <strong>for</strong> WindowsServices <strong>for</strong> UNIX from http://www.inte ropsystems.com/tools/warehouse.htm.This technology option, however, has not been fully tested as a part of development ofthis solution and there<strong>for</strong>e has not been detailed further.Introduction to the Perl DBI ArchitectureThere are several different modulesavailable <strong>for</strong> use with Perl that extend the capabilitiesof the language. One of these modules, the Database Independent Interface (DBI),

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 225provides a common programming interface <strong>for</strong> several different proprietary databases,including <strong>Oracle</strong> and SQL Server. DBI offers a single set of functions or methods that caninteract with the databases. These functions <strong>for</strong>m an abstraction layer that allows theprogrammer to write code using generic DBI calls without needing specific APIknowledge <strong>for</strong> the particular database. This layer makes the Perl code portable acrossdatabases.These generic DBI calls are then interpreted into RDBMS-specific functions usingspecialized Database Driver (DBD) modules. A DBD is a database-specific driver thattranslates DBI calls to the target database. The DBI API <strong>for</strong>wards the call to theappropriate database driver module, which then provides support, such as the dynamicload ing of drivers, error-checking, and management. Figure 12.1 provides a visualrepresentation of path from a Perl script to the backend database using DBI-DBD.Figure 12.1Perl communication with databases using DBI API and DBD driversDBI also supports the Open Database Connectivity (ODBC) interface. While DBI itself isan abstraction layer, ODBC <strong>for</strong>ms another additional abstraction layer. This layer,consisting of an ODBC driver and ODBC driver manager mirrors the functions of the DBIand DBD within Perl. If the current solution utilizes ODBC, then a port using ODBC mayprovide the most direct solution. In other instances, ODBC may simply duplicate otherlaye rs and add additional processing overhead. In these situations, ODBC is notrecommended. Figure 12.2 shows the path from Perl script to backend databaseinvolving ODBC drivers.Figure 12.2ODBC adds additional layers of connectivity between the application and databaseScenario 1: Interoperation of Perl on UNIX withSQL ServerInteroperation between a UNIX-based Perl application and a SQL Server database ispossible because of the availability of a driver that interfaces between thesetechnologies. Because of the DBI API, this type of migration is usually a relatively simpleprocess. Only minimal changes may need to be made to the Perl application's source

226 Developing: Applications — <strong>Migrating</strong> Perlcode.The cases described in this section discuss options available <strong>for</strong> Perl applicationsusing ODBC or <strong>Oracle</strong> drivers. The following cases assume that the Perl applicationcurrently uses either the ODBC DBD or the <strong>Oracle</strong> DBD within the existing solution.Case 1: Interoperating an ODBC DBD ApplicationIf the original application was written using ODBC DBD, then the best migration option isto continu e to use this driver. Because ODBC is not database-specific, no changesshould need to be made to the application's source code. The only changes that need tobe made concern connectivity with the SQL Server database. T o interoperate the Perl application using ODBC, follow these common steps:1. Install the ODBC driver.The DBD::ODBC module requires a driver manager and a driver to interact withSQL Server. DBD::ODBC is packaged with the Independent ODBC (iODBC) drivermanager from OpenLink Software (http://www.openlinksw.com/). For morein<strong>for</strong>mation about this driver, refer tohttp ://www.freetds.org/userguide/perl.htm#DBD.ODBC. Another driver manager,unixODBC, that could be used in an interoperation scenario is available fromhttp://www.freetds.org/user guide/prepodbc.htm.FreeTDS is a popular ODBC driver used to connect to SQL Server from a UNIX-source implementation of Tabular Databased application. FreeTDS is an openStream (TDS) protocol that allows the application native access to SQL Server.OpenLink also offers drivers <strong>for</strong> SQL Server that use the FreeTDS implementationof TDS. Detailed instructions <strong>for</strong> building and configuring this driver are available athttp://www.freetds.org/userguide/perl.htm.For detailed steps on installing the unixODBC or FreeTDS drivers, see AppendixD: "Installing Common Drivers and Applications." Even though the discussion isrelated to installing FreeTDS in a Windows Services <strong>for</strong> UNIX environment, itapplies equally to UNIX as well.2. Create a SQL Server data source.To function, ODBC needs a data source to connect to the database. The DataSource Name (DSN) is generally defined in an odbc.ini file that is used by thedriver manager. The DSN is used by the driver manager to load the ODBC driver.iODBC offers a graphical user interface to set up the DSN. Complete instructionsare available from http://www.iodbc.org/index.php?page=docs/odbcstory.The DSN can also be configured by manually modifying the odbc.ini file. Thefollowing example file uses an <strong>Oracle</strong> DSN.[ODBC Data Sources]ORA_HR_DB=Sample <strong>Oracle</strong>8 dsn[ORA_HR_DB]Driver=/opt/odbc/lib/ivor8x01.soDescription=<strong>Oracle</strong>8ServerName=uxdbp1LogonID=davebPassword=cougarThis configuration file can be modified to use the SQL Server DSN, as shown inthe following example. Note that the [ORA_HR_DB] section is replaced with[SS_HR_DB]. Though most of the keys remain, the values are modified to allow <strong>for</strong>the SQL Server data source.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 227[ODBC Data Sources]SS_HR_DB=Sample MS SQLServer[SS_HR_DB]Driver=/usr/local/freetds/lib/libtdsodbc.soDescription=SQL Server 2000Database=hrappUID=davebPWD=cougarAddress=win2kdbp1,1433Note The isql command line utility can be used to check the validity of the DSNentry when using unixODBC. This allows you to ensure that the entries in theodbc.ini are correct. The syntax <strong>for</strong> use is:isql -v DSN username password3.Test the connectivity.iODBC contains a utility named odbctest which can be used to test the DSNentries and interact with the database by connecting and issuing queries directlywithout any code. The syntax <strong>for</strong> per<strong>for</strong>ming this test is:odbctest "DSN=SS_HR_DB;UID=daveb;PWD=cougar"4. Change the existing application to use SQL Server as data source.The following sample source Perl program from an <strong>Oracle</strong> environment containsfunctions to connect, prepare, execute, bind, and disconnect. Compare thesefunctions with the Perl code in the following example. Minor adjustments are madeto allow <strong>for</strong> the data source change.#Load the DBI moduleuse DBI;my $connectstring_oracle = 'ora_hr_db';my $username = 'daveb';my $password = 'cougar';my $tablename = 'Employee_Info';#Connecting to <strong>Oracle</strong> DB using ODBCmy $dbh = DBI->connect(" dbi:ODBC:$connectstring_oracle", "$username","$password");#Preparing the SQL statement$sth = $dbh->prepare("insert into $tablename (last_name) values (?)");#Binding the value to the parameter at run time.$sth->bind_param( 1,"LName);#Executing the query$sth->execute() or warn $sth->errstr(); # check <strong>for</strong> error$sth->finish();

228 Developing: Applications — <strong>Migrating</strong> Perl#Disconnect from <strong>Oracle</strong> database$dbh->disconnect or warn "Can't disconnect from the <strong>Oracle</strong>$connectstring_oracle database: $DBI::errstr\n";The same functions are modified to use a SQL Server data source in the followingexample:my $connectstring_oracle = 'ora_hr_db';my $username = 'daveb';my $password = 'cougar';my $tablename = 'Employee_Info';#Connecting to <strong>Oracle</strong> DB using ODBCmy $dbh = DBI->connect("dbi:ODBC:$connectstring_oracle", "$username","$password")tomy $connectstring_ss = 'ss_hr_db';my $username = 'daveb';my $password = 'cougar';my $tablename = 'Employee_Info';#Connecting to SQL Server DB using ODBCmy $dbh = DBI->connect("dbi:ODBC:$connectstring_ss", "$username", "$password")5. Change all embedded SQL statements to T-SQL.This is a step common to all migrations. Refer to Chapter 11, "Developing:Applications — <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> a detailed discussion on modifying<strong>Oracle</strong> SQL to be SQL Server-compliant.Case 2: Interoperating an <strong>Oracle</strong> DBD ApplicationIf the original application was written using the <strong>Oracle</strong> DBD, there are two possibleoptions that can be evaluated. The recommended option is to replace the <strong>Oracle</strong> DBDwith a Sybase DBD. The second option is to migrate to an ODBC framework similar tothe one seen in "Case 1: Interoperating an ODBC DBD Application." Sybase DBD offersbetter per<strong>for</strong>mance than ODBC.Migrate to SQL Server Using Sybase DBDBecau se SQL Server was originally based on the Sybase data structure, it is possible touse the Sybase DBD to connect to SQL Server using a SQL Server driver. To use the Sybase DBD to connect to SQL Server using a SQL Server driver,follow these steps:1. Install SQL Server library support.The FreeTDS driver is needed <strong>for</strong> this method. Instructions <strong>for</strong> installing andconfiguring the driver are located in Appendix D, "Installing Common Drivers andApplications." Even though the discussion is related to installing FreeTDS in aWindows Services <strong>for</strong> UNIX environment, it applies equally to UNIX as well.Because the driver is not being used with ODBC, the -disable-odbc switch can beused with the configure command while installing FreeTDS. Details on the use ofthis command are availa ble at http://www.freetds.org/userguide/config.htm.2. Configure the data source.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 229After FreeTDS is installed, the freetds.conf file should be modified to include theSQL Server database in<strong>for</strong>mation. A sample entry is shown in the followingexample:[SS_HR_DB]host = win2kdbp1 # or IP addressport = 1433tds version = 8.03. Install the Sybase DBD module.For more in<strong>for</strong>mation on installing this Perl module, refer tohttp://search.cpan.org/~mewp/DBD-Sybase/Sybase.pm.In addition, the SYBASE environment variable should be set to the location of theFreeTDS installation. If using bash or ksh, the following commands can be used:4.export SYBASE=/usr/local/freetdsModify the application's source code.Minor changes will need to be made to the source code to allow <strong>for</strong> the datasource change. The following sample code shows some different implementationoptions of the Perl language that may appear in your existing source code.Compare these to the second code sample that has been modified to use theSybase DBD.# load the DBI moduleuse DBI;# Connect to the <strong>Oracle</strong> Databasemy $dbh = DBI->connect("dbi:<strong>Oracle</strong>: ora_hr_db ",'userName','password',{RaiseError = > 1,AutoCommit => 0}) || die "Database connection not made: $DBI::errstr";#Prepare a SQL statementmy $sql = qq{ SELECT id, name, title,my $sth = $dbh->prepare( $sql );phone FROM employees };#Execute the statement$sth->execute();my( $id, $name, $title, $phone );# Bind the results to the local variables$sth->bind_columns( undef, \$id, \$name, \$title, \$phone );#Retrieve values from the result setwhile( $sth->fetch() ) {print "$name, $title, $phone\n";}

230 Developing: Applications — <strong>Migrating</strong> Perl#Close the connection$sth->finish();$dbh->disconnect();5. Change the connection to the Sybase DBI and SQL Server DSN.The script in Step 4 has been rewritten to use DBD::Sybase. Note that the changeshave been made in the header <strong>for</strong> the DBD and in the connection string <strong>for</strong>SQL Server. The rest of the Perl code is untouched by this change. This modifiedcode is shown in the following example.# load the DBI moduleuse DBI;use DBD::Sybase;BEGIN{$ENV{SYBASE} = "/usr/local";}# Connect to the SQL Server Databasemy $dbh = DBI->connect( “dbi:Sybase:server=ss_hr_db;database=hrapp”,'userName','password',{RaiseError => 1,AutoCommit = > 0}) || die "Database connection not made: $DBI::errstr";#Prepare a SQL statementmy $sql = qq{ SELECT id, name, title, phone FROM employees };my $sth = $dbh->prepare( $sql );#Execute the statement$sth->execute();my( $id, $name, $title, $phone );# Bind the results to the local variables$sth->bind_columns( undef, \$id, \$name, \$title, \$phone );#Retrieve values from the result setwhile( $sth->fetch() ) {print "$name, $title, $phone\n";}#Close the connection$sth->finish();$dbh->disconnect();

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 2316.Change all embedded SQL statements to T-SQL.Refer to Chapter 11, "Developing: Applications — <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> adetailed discussion on modifying <strong>Oracle</strong> SQL to be SQL Server-compliant.Migrate to SQL Server Using ODBC To migrate an <strong>Oracle</strong> DBD connection to ODBC, follow these steps:1. Install the ODBC driver.FreeTDS should be installed. For more in<strong>for</strong>mation see Appendix D, "InstallingCommon Drivers and Applications." Even though the discussion is related toinstalling FreeTDS in a Windows Services <strong>for</strong> UNIX environment, it applies equallyto UNIX as well.2. Configure the DSN settings.The steps <strong>for</strong> creating an ODBC DSN have been shown in "Case 1: Interoperatingan ODBC DBD Application."3. Install the ODBC DBD module.Installation instructions are available at http://search.cpan.org/dis t/perl/INSTALLand http://www.easysoft.com/products/2002/perl_dbi_dbd_odbc.phtml#3_0In addition, the following environment variables need to be set:● ODBCHOME. The directory where ODBC driver manager is installed.● DBI_DSN. The dbi data source.● DBI_USER. The username to connect to the database.● DBI_PASS. The password <strong>for</strong> the database username.4. Modify the source code.The original script written <strong>for</strong> use with DBD::<strong>Oracle</strong> has to be changed to connectto SQL Server through the ODBC DSN. Changes are limited to the connect()method as shown in the following code.# load the DBI moduleuse DBI;# Connect to the <strong>Oracle</strong> Databasemy $dbh = DBI->connect("dbi:ODBC:ss_hr_db",'userName','password',{RaiseError => 1,AutoCommit => 0}) || die "Database connection not made: $DBI::errstr";#Prepare a SQL statementmy $sql = qq{ SELECT id, name, title, phone FROM employees };my $sth = $dbh->prepare( $sql );#Execute the statement$sth->execute();my( $id, $name, $title, $phone );

232 Developing: Applications — <strong>Migrating</strong> Perl# Bind the results to the local variables$sth->bind_columns( undef, \$id, \$name, \$title, \$phone );#Retrieve values from the result setwhile( $sth->fetch() ) {print "$name, $title, $phone\n";}#Close the connection$sth->finish();$dbh->disconnect();Note ODBC connections can also be made without using DSN sources. Thedifference from a DSN is that the required configuration in<strong>for</strong>mation is embeddedin the Perl code instead of residing in a separate initialization file. The followingexample shows a non-DSN connection:my $dsn = 'DBI:ODBC:Driver={SQL Server}';my $host = 'hostname';my $database = 'dbname';my $user = 'username';my $auth = 'password';my($dbh) = DBI->connect("$dsn;$host;$database",$user,$auth,{ RaiseError => 1, AutoCommit => 1});5. Change all embedded SQL statements to T-SQL.Refer to chapter 11, "Developing: Applications — <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> adetailed discussion on modifying <strong>Oracle</strong> SQL to be SQL Server-compliant.Scenario 2: Porting the Perl Application to WindowsThe migration of Perl applications in a UNIX environment to Windows and moving thebackend to a SQL Server database is not much more ef<strong>for</strong>t than that needed under theinteroperation scenario. It is possible to port the Perl application to both the .NET and theWin32 environment. The port to .NET is made possible by the availability of the utilityPerlNET, which can wrap Perl programs into a .NET component. However, theapp lication has to be ported from the UNIX environment to Windows environment be<strong>for</strong>ethe conversion to .NET can be per<strong>for</strong>med. Details about PerlNET are available athttp://aspn.activestate.com/ASPN/docs/PDK/6.0/PerlNET.html#perlnet_top.There are a few additional steps that should be followed to successfully move the Perlapplication to Win32. These steps are discussed in the following two cases.Case 1: Porting a Perl Application using ODBC DBD To port the Perl application to the Windows environment, follow these steps:1. Install Perl in the target Windows environment.ActiveState Perl is available from http://www.activestate.com. For more in<strong>for</strong>mationon installing ActivePerl, see Appendix D, "Installing Common Drivers andApplications."2. Install DBI and DBD::ODBC.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 233The DBI and DBD::ODBC modules can be installed using Perl Package Manager(PPM), which is installed with ActivePerl. PPM is an interactive command line utilitywhich can be launched from the command line by typing ppm.Download the DBI and DBD::ODBC files to a local directory—<strong>for</strong> example,c:\perlppd. These files can be downloaded fromhttp://ppm.activestate.co m/PPMPackages/zips/ .The modules can be installed by typing the following commands:PPM> rep add new c:\perlppdPPM> install DBIPPM> install DBD-ODBCPPM> quit3. Install the ODBC driver.There are several available options <strong>for</strong> acquiring and installing an ODBC driver <strong>for</strong>SQL Server. These options include:● An ODBC driver <strong>for</strong> SQL Server is included as part of the SQL Serverdistribution CD and is installed as part of the SQL Server client install. Refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/howtosql/ht_install_029l.asp <strong>for</strong> in<strong>for</strong>mation on installing the SQL Serverclient.● OpenLink software offers an ODBC solution that eliminates the need to installSQL Server client software on the server on which the Perl application will run.Details on this driver are available at http://uda.openlinksw.com/odbc/st/odbc-sqlserver-st/.● DataDirect offers Connect <strong>for</strong> ODBC drivers that also provide clientless accessto SQL Server. Details are available athttp://www.datadirect.com/products/odbc/index.ssp.4.Configure the ODBC data source.An ODBC data source can be configured by modifying odbc.ini as shown in the"Case 1: Interoperating an ODBC DBD Application" section of Scenario 1. Thedata source can also be configured using the ODBC Data Source Administratorutility that is bundled with Windows. This utility can be accessed by accessing fromthe Control Panel by choosing Administrative Tools, then Data Sources(ODBC). Somedatabase vendors also provide utilities to configure DSNs.

234 Developing: Applications — <strong>Migrating</strong> PerlFigure 12.3Configuring the ODBC System DSNNote In Windows, DSNs should be created as a System DSN and not as a UserDSN because of permissions restrictions associated with the latter.Further steps <strong>for</strong> creating a data source are available athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/howtosql/ht_6_odbcht_1oqc.asp.5. Change the application to use SQL Server as the data source.The move to Windows does not add any overhead in terms of modifications to theapplication. The changes are driven by the change in DSN and are similar tochanges discussed in the "Case 1: Interoperating an ODBC DBD Application"section of Scenario 1.6. Change all embedded SQL statements to T-SQL.This is a step common to all migrations. Refer to Chapter 11, "Developing:Applications — <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> a detailed discussion on modifying<strong>Oracle</strong> SQL to be SQL Server-compliant.Case 2: Porting a Perl Application Using <strong>Oracle</strong> DBDWhen migrating from a UNIX plat<strong>for</strong>m to a Windows plat<strong>for</strong>m, there are two options toreplace the DBD::<strong>Oracle</strong> module. One option is to use the DBD::ODBC module. Theother is to use ActiveX Data Objects (ADO) through the DBD::ADO module.Using DBD::ODBC is recommended in most instances and is discussed in greater detailin the "Case 1: Interoperating an ODBC DBD Application" section of Scenario 1.DBD::ADO is a DBI driver that acts as an interface to other lower-level database drivers

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 235within Windows. DBD::ADO requires the DBD::ODBC module to function. UsingDBD::ADO will add an additional connectivity layer to the solution and should only beimplemented if the application needs to take advantage of the OLE DB APIs. This drivercan then be used to connect to and access data from any ADO data source.Migrate to DBD::ADO To migrate to DBD::ADO, follow these steps:1. Install ActivePerl.ActivePerl is a Windows-based Perl engine available fromhttp://www.a ctivestate.com. For detailed installation instructions, see Appendix D,"Installing Common Drivers and Applications."2. Install DBI.The DBI module can be installed using Perl Package Manager (PPM), which isinstalled with ActivePerl.3. Install DBD::ODBC using PPM.4. Install the ODBC driver.5. Configure the ODBC data source.6. Install ADO.The DBD::ADO module requires Microsoft ADO version 2.1 or later to workreliably. ADO drivers are available from Microsoft as part of the Microsoft DataAccess Component (MDAC) available athttp://msdn.microsoft.com/data/technologyinfo/mdac.Download the DBD::ADO module files to a local directory—<strong>for</strong> example, c:\perlppd.The ADO module can be downloaded fromhttp://ppm.activestate.com/PPMPackages/zips/.This module can be installed from Perl Package Manager (PPM).Type ppm at the command line to start the package manager, and then type thefollowing commands:PPM. Rep add new c:\perlppdPPM> install DBIPPM> install DBD-ADOPPM> quit7. Modify the connection string to use ADO. No other changes should need to bemade to the source code. A sample ADO connection string is shown in thefollowing example:use DBI;my $dsn ="Provider=sqloledb;Trusted_Connection=Yes;Server=win2kdbp1;Database=hrapps";$dbh = DBI->connect("dbi:ADO:$dsn", $user, $passwd);Calling stored procedures is supported by DBD::ADO using the ODBC style callprocedure_name(). An example <strong>for</strong> calling a procedure ismy $sth = $dbh->prepare("{call procedure name (?)}");Parameters can be either input or output parameters. Parameters are bound asseen in earlier examples.8. Change all embedded SQL statements to T-SQL.This is a step common to all migrations. Refer to Chapter 11, "Developing:Applications — <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> a detailed discussion on modifying<strong>Oracle</strong> SQL to be SQL Server-compliant.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 23713Developing: Applications —<strong>Migrating</strong> PHPIntroduction and GoalsThis chapter explores the options available to maintain connectivity of PHP: HypertextPreprocessor (PHP) applications as part of the <strong>Oracle</strong> to Microsoft® SQL Servermigration project. In PHP, the logic to interact with databases is provided by database-functions to per<strong>for</strong>mspecific modules (or drivers). These modules have specializeddatabase-related tasks and can be replaced to accommodate a SQL Server backend withrelative ease.PHP is an open source, server-side, cross-plat<strong>for</strong>m scripting language used to createdynamic Web pages. Like any other Common Gateway Interface (CGI), PHP can providedynamic, data-driven characteristics to static HTML <strong>for</strong>ms or pages.As discussed in Chapter 2, "Envisioning Phase," there are four different strategiesavailable <strong>for</strong> transitioning applications in an <strong>Oracle</strong> to SQL Server migration project. Thestrategies are:● Interoperate the application with the UNIX environment.● Port or rewrite the application to the Microsoft .NET plat<strong>for</strong>m.● Port or rewrite the application to the Microsoft Win32® plat<strong>for</strong>m.● Quick port using the Microsoft Windows® Services <strong>for</strong> UNIX 3.5 plat<strong>for</strong>m.Because of the unique characteristics of PHP, some ofthan others.these strategies are more feasibleFor example, because PHP can be ported to Windows, there is no need to rewrite theapplication <strong>for</strong> .NET or Win32 unless the existing solution's source code is not available.Because the available drivers <strong>for</strong> .NET are still in beta, the porting has to be done to aWin32 environment, Also, because the application can run within the Windowsenvironment, a quick port using Windows Services <strong>for</strong> UNIX is not necessary in mostcases.Bas ed on the available migration strategies, two scenarios can be developed to migratePHP applications. These scenarios include:● Scenario 1: Interoperating PHP on UNIX with SQL ServerIf the business requirementsdo not include eliminating the UNIX environment, aninteroperation strategy can be implemented quickly. Few changes need to be

238 Developing: Applications — <strong>Migrating</strong> PHP●made to the source code and installing a new driver allows the PHP application toconnect to a SQL Server database. If the migration is per<strong>for</strong>med in phases,interoperation can be used as an interim step.Scenario 2: Porting the Application to Win32PHP applications can also be ported to run natively on the Windows plat<strong>for</strong>m. Aswith interoperation, few changes need to be made to the source code.Available options are discussed <strong>for</strong> each scenario in separate cases. Each case listssteps required to connect the PHP application to the SQL Server data source. Alsoincluded are discussions on the differences between the various <strong>Oracle</strong> and SQL Serverfunctions. When applicable, sample source code is provided to illustrate changes thatneed to be made.Note If your PHP scripts use UNIX system calls extensively (such as frequent use ofexec, passthru, popen, or the backtick (`)), porting them to Windows Services <strong>for</strong>UNIX/Interix may be a suitable option because Interix has more support <strong>for</strong> the desiredsystem calls. Chapter 2, "Envisioning Phase," provides a more detailed discussion ofwhen choosing Windows Services <strong>for</strong> UNIX would be more appropriate when movingto a Windows-based plat<strong>for</strong>m.You will need the following to implement this option (porting PHP applications toWindows Services <strong>for</strong> UNIX/SQL Server):● A port of PHP <strong>for</strong> Interix downloadable from Interop Systems athttp://www.interopsystems.com/tools/warehouse.htm, which includes the capabilityof using DBLib, CTLib and ODBC. The PHP distribution will have to be compiled<strong>for</strong> using a specific database connectivity library.● A connectivity driver to the SQL Server database. This is provided by the port ofFreeTDS on Interix and is downloadable from Interop Systems athttp://www.interopsystems.com/tools/db.htm. FreeTDS provides three connectivityoptions <strong>for</strong> the PHP application to connect to the SQL Server database. Twooptions go through the libraries DBLib and CTLib, which provide connectivity toboth Sybase and SQL Server. The third is the ODBC driver, which can be used toaccess any ODBC database (including SQL Server).This technology option, however, has not been fully tested as a part of development ofthis solution and there<strong>for</strong>e has not been detailed further.PHP ModulesPHP contains a rich set of options <strong>for</strong> interfacing with common proprietary databases,including <strong>Oracle</strong> and SQL Server. These interfaces are available through PHP as internalfunctions or extensions. The database-related functions are grouped into modules which

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 239must be compiled into the PHP installation be<strong>for</strong>e use. These modules are enabled byspecifying them in the configuration file (php.ini).Figure 13.1PHP modules (functions) that can access <strong>Oracle</strong>Figure 13.2PHP modules (functions) that can access SQL ServerThe following modules are commonly used with <strong>Oracle</strong> databases. Each is discussed indetail in this chapter:● <strong>Oracle</strong>(ORA) functionsORA is a set of functions used to access <strong>Oracle</strong> databases.The php_oracle value in the php.ini file (extension=php_oracle.dll) is used toenable functions. The functions in this module can be identified by the ora_ prefix,such as ora_logon().● <strong>Oracle</strong> 8 (OCI8) functions

240 Developing: Applications — <strong>Migrating</strong> PHP●OCI8 is a set of functions based on <strong>Oracle</strong> Call Interface (OCI) used to access<strong>Oracle</strong> databases, including 8i and 9i releases. This module is more flexible thanthe standard <strong>Oracle</strong> functions.The php_oci8 value in the php.ini file (extension=php_oci8.dll) is used to enablethe functions. The set of functions that are in this module can be identified by theoci_ prefix, such as oci_logon(). Be<strong>for</strong>e PHP 5.0, every oci_ function was namedwith an oci prefix. Although the functions with the oci prefix are still available, theyare now deprecated.ODBC functionsA modified version of ODBC that provides a unified driver <strong>for</strong> native support <strong>for</strong>several databases is available <strong>for</strong> PHP. ODBC support is integrated with PHP and,unlike the modules needed <strong>for</strong> ORA and OCI8, no extensions need to be specified.ODBC has the advantage of allowing applications to be written which, theoretically,are independent from the RDBMS. If the RDBMS changes, only the driver willneed to be changed, not the code.ODBC function calls are handled by a driver manager that passes the calls to aspecific driver <strong>for</strong> the target database <strong>for</strong> execution. The iODBC driver manager iscommonly used with PHP to connect to databases on Windows. iODBC(h ttp://www.iodbc.org) is an open source ODBC driver manager and the SDK ismaintained by Open Link Software (http://www.openlinksw.com). iODBC calls usean odbc_ prefix. For example, odbc_connect() utilizes the ODBC driver manager.Another open source project, named after the unixODBC project, has developed adriver manager called unixOD BC (http://www.unixodbc.org). The unixODBC callsuse the three-letter SQL prefix. For example, SQLconnect() uses the unixODBCdriver manager.Note The function phpinfo() can be called to reveal the extensions that have beenloaded into PHP. A simple script containing the following line is sufficient to implementthis call:Scenario 1: Interoperating PHP on UNIX withSQL ServerIt is possible to interoperate between PHP applications in a UNIX environment andSQL Server databases using Microsoft® SQL Server functions or through an ODBCinterface. Each API has its own function calls to connect to the database and executestatements. These APIs vary in support <strong>for</strong> common functions such as those related tocursors and statements.Case 1: Interoperating a PHP Application Using ORAFunctionsIf the existing PHP solution uses ORA functions, then the best alternative is to replacethem with Microsoft SQL Server (MSSQL) functions. This modification will requirereplacing the current driver with one that supports the MSSQL functions. One of thedrivers that can be used is FreeTDS (http://www.freetds.org).FreeTDS is a set of libraries <strong>for</strong> UNIX and Linux that allows programs to interact withMicrosoft SQL Server. Using the FreeTDS libraries, PHP's mssql_xxx() functions can beused to directly access a SQL Server databasefrom a UNIX or Linux computer. FreeTDS

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 241is an open source implementation of the Tabular Data Stream protocol used bySQL Server <strong>for</strong> its clients. The FreeTDS C libraries are freely available under the terms ofthe GNU GPL license.The protocol version also affects how database servers interpret commands. MicrosoftSQL Server 2000 is known to behave differently with versions 4.2 and 8.0 of FreeTDS.version 8.0 is recommended <strong>for</strong> compatibility with SQL Server tools. To interoperate a PHP application using ORA functionality, follow thesecommon steps:1. Install the FreeTDS SQL Server libraries.D ownload the source code from http://www.freetds.org/software.html. Theinstallation process is very similar to that detailed in Appendix D, "InstallingCommon Drivers and Applications," except that the installation is occurring in UNIXinstead of Windows Services <strong>for</strong> UNIX.Note FreeTDS should be compiled with the --enable-msdblib option.2. Recompile PHP to use MSSQL functions.Refer to http://www.free tds.org/userguide/php.htm <strong>for</strong> more in<strong>for</strong>mation oncompiling PHP.Note PHP should be configured with the --with-mssql[=DIR] switch, where DIR isthe location of the FreeTDS libraries. For example, from the PHP source directory,type:./configure --with-mssql=/usr/local/freetds3. Enable MSSQL functions.Be<strong>for</strong>e MSSQL functions can be used, they must be enabled and initialized <strong>for</strong> useby uncommenting or adding the following line in the initialization file php.ini.extension=php_mssql.dll4. Verify the installation.Verify that the module i s installed by executing the phpinfo() function. MSSQLshould appear in the list of modules.5. Change all embedded SQL statements to T-SQL.Refer to chapter 11, "Developing: Applications — <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> adetailed discussion on modifying <strong>Oracle</strong> SQL to be SQL Server-compliant.6. Modify the PHP application code.The following sample sour ce code is used to illustrate the changes required whenmigrating PHP code from ORA functions to MSSQL functions. Pay specialattention to the differences between these code sections.Note MSSQL does not have functions to create and drop cursors. Implicitcursorsare used to handle results returned.

242 Developing: Applications — <strong>Migrating</strong> PHPThe following example is sample ORA-based PHP code that executes a simplequery and retrieves results using a cursor operation:The following example is the same code modified to MSSQL-based PHP code:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 243$mycursor = mssql_query($sql);// Display in<strong>for</strong>mationwhile ($row = mssql_fetch_array($mycursor)){echo "RESULT: " . $row['last_name'] . ", " . $row['salary'] . "\n";}// Close connectionmssql_close($conn);?>Database server in<strong>for</strong>mation can also be referenced from freetds.conf, as shown inthe following configuration in<strong>for</strong>mation./* freetds.conf[SQLServer]host = win2kss1port = 1433tds version = 8. 0*/To use the freetds.conf entry, the connection code will change as follows:// specify path to fileputenv(FREETDSCONF=/usr/local/freetds.conf’)$conn=mssql_connect(‘SQLServer’, $username, $password);The following table provides a mapping between key ORA functions and the respectiveMSSQL functions. ORA functions that do not have a matching MSSQL function aredenoted with a hyphen. A discussion of handling these disparate functions appears in the"Common Function Translation Issues" section later in this chapter.Table 13.1: Mapping Between ORA and MSSQL FunctionsOperation Task ORA function MSSQL functionConnection Open connection ora_logon() mssql_connect()Close connection ora_logoff() mssql_close()Persistent ora_plogon() mssql_pconnect()connectionCursorOpen cursor ora_open() -Close cursor ora_close() -Pa rsing Parse statement ora_parse( ) -Binding Bind variable ora_bind() mssql_bind()ExecutionExecute statement ora_exec() mssql_execute()mssql_query()Prepare and ora_do() mssql_execute()executemssql_query()Fet ching Fetch rowora_fetch()ora_fetch_intomssql_fetch_row()mssql_fetch_array()Fetch column ora_getcolumn() mssql_fetch_fieldTransactionCommitora_commiton() -Managementora_commitoff()

244 Developing: Applications — <strong>Migrating</strong> PHPOperation Task ORA function MSSQL functionora_commit()Rollbackora_rollback() -Error Handling Error checking ora_error()-ora_errorcode()OthersName of result ora_columnname() mssql_field_name()columnSize of result ora_columnsize() mssql_field_length()columnDatatype of result ora_columntype() mssql_field_type()columnNumber of rowseffectedora_numrows() mssqp_num_rows()Number of columns ora_numcols() mssql_num_fields()returnedCase 2: Interoperating a PHP Application Using OCI8Functions To interoperate using OCI8, follow these common steps:As with Case 1 "Interoperating a PHP Application Using ORA Functions", the best alternative<strong>for</strong> OCI8 functions is to replace them with MSSQL calls. Most of the steps are the samebetween this procedure and the p rocedure in the "Case 1: Interoperating a PHP ApplicationUsing ORA F unctions" section of this scenario. As a result, these steps are not described indetail here.1. Install the FreeTDS SQL Server libraries.2. Compile PHP to use MSSQLAPIs.3. Enable MSSQL functions within php.ini.4. Verify the installation using phpinfo().5 . Change all embedded SQL statements to T-SQL.Refer to Chapter 11, "Developin g: Applications — <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> adetailed discussion on modifying <strong>Oracle</strong> SQL to be SQL Server-compliant.6. Modify application code to reflect the new drivers.The following sample source code is used to illustrate the changes required in PHPcode when replacing OCI8 functions with MSSQL functions.The following example is the original OCI8-based PHP code:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 245$sql1 = OCIParse($conn, "INSERT INTO countries VALUES (‘US‘,‘United States ofAmerica’, 2)");OCIExecute($sql1);// Insert SQL statement with binding$var1 = ‘MX’;$var2 = ‘Mexico”;$var3 = 3;$sql2 = OCIParse($conn, "INSERT INTO countries VALUES (:bind1, :bind2,:bind3); ");OCIBindByName($sql2, ":bind1", $var1);OCIBindByName($sql2, ":bind2", $var2);OCIBindByName($sql2, ":bind3", $var3);OCIExecute($sql2);echo OCIRowCount($sql2) . " rows inserted. ";// CommitOCICommit($conn);// Close connectionOCILogoff($conn);?>The following example is the same PHP source code modified to use the MSSQLdrivers. Note the difference in the commit function.

246 Developing: Applications — <strong>Migrating</strong> PHP// Close connectionmssql_close($conn);?>Table 13.2 maps the equivalent calls between OCI8 and MSSQL functions. A hyphen isused when a similar function does not exist in MSSQL. A discussion on handling thesedisparate functions is available in the "Common Function Translation Is sues" section laterin this chapter.Table 13.2: Mapping Between OCI8 and MSSQL FunctionsOperation Task OCI8 Functions MSSQL FunctionsConnection Open connection ociLogon() mssql_connect()Close connection ociLogoff() mssql_close()Persistent ociPLogon() mssql_pconnect()connectionCursor Open cursor ociNewCursor() -Close cursor ociFreeCursor() -Statement Free statement oci_free_statement() mssql_free_statement()Parsing Parse statement ociParse() -ExecutionExecuteociExecute()mssql_execute()statementmssql_query()Fetching Fetch row ociFetch() mssql_fetch_row()TransactionManagementCommitRollbackociCommit()ociRollback()--Error Error checking ociError()-HandlingOthersName of result ociColumnName() mssql_field_name()columnSize of result ociColumnSize() mssql_field_length()columnDatatype of ociColumnType() mssql_field_type()result columnNumber of rows ociRowCount() mssql_num_rows()effectedNumber of ociNumCols() mssql_num_fields( )columns returnedCase 3: Interoperating a PHP Application UsingODBC FunctionsWhile migrating from <strong>Oracle</strong> to SQL Server, no cha nges will be needed to the ODBCcalls themselves; the availability of SQL Server-specific drivers <strong>for</strong> the UNIX environmentand the capabilities of the dr iver manager to work with these drivers definethe changesthat must be made. The best choice <strong>for</strong> interoperating with SQL Server is offered by the

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 247FreeTDS driver, which is supported by the iODBC driver manager of the sourceenvironment.Other options available include Easysoft's ODBC-ODBC Bridge (OOB) and OpenLink'sUniversal Data Access drivers. To interoperate using ODBC functions, follow these common steps:The following steps are required to interoperate PHP applications with SQL Server.1. If needed, install ODBC software.It is assumed that the iODBC driver manager is alre ady installed and is being usedto connect to <strong>Oracle</strong>. If this is not true, then either the iODBC or the unixODBCdriver manager must be installed.The iODBC driver manager can be downloade d fromhttp://www.openlinksw.com/iodbc/. Installation instru ctions are availableinAppendix D, "Installing Common Drivers and Applications."The unixODBC driver manager can be downloaded from http://www.u nixodbc.org/ .Installation instructions are also available in Appendix D, "Installing CommonDrivers and Applications."2. Install the SQL Server driver.The most popular ODBC driver to connect to SQL Server from a UNIX operatingsystem is FreeTDS. FreeTDS is an open source implementation of TDS that allowsUNIX-based programs native access to SQL Server. OpenLink also offers drivers<strong>for</strong> SQL Server that use the FreeTDS implementation of TDS. Installationinstructions are located in Appendix D, "Installing Common Drivers andApplications."An ODBC-ODBC bridge to SQL Server is available from Easysoft. For detailedinstructions on enabling ODBC support under PHP, refer tohttp://www.easysoft.com/produ cts/2002/apache.phtml.OpenLink (http://www.openlinks w.com) also offers single-tier and multitierUniversal Data Access drivers.3. Recompile PHP to use ODBC functions.To be capable to use the SQL Server driver, PHP must be recompiled with ODBCfunctions. This procedure will vary based on the ODBC driver that is installed.Refer the following resources <strong>for</strong> more in<strong>for</strong>mation.● FreeTDS — http: //www.freetds.org/userguide/php.htm● Easysoft — http://www.easysoft.com/products/2002/apache.phtml● OpenLink — http://docs.openlinksw.com4. Configure the Data Source Name (DSN).ODBC needs an ODBC data source to connect to the database. The DSN isgenerally defined in an odbc.ini file that the driver manager uses to load the ODBCdriver.When using FreeTDS, the DSN can also be configured by modifying the odbc.inifile. A SQL Server DSN should be similarly configured to the following example.[ODBC Data Sources]SS_HR_DB=Sample MS SQLServer[SS_HR_DB]Driver=/usr/local/freetds/lib/libtdsodbc.soDescription=SQL Server 2000Server=win2kdbp1

248 Developing: Applications — <strong>Migrating</strong> PHPPort=1433Database=hrappLogonID=davebPassword=cougar5. Check the connection.In iODBC, the command line query program odbctest can be used to test the DSNconnectivity. If using unixODBC, the isql utility can be used to do this.6. Modify the application source code to reflect the new data source.Because ODBC is a generic interface to any database, no changes are required inthe application code except to connect to the SQL Server database. The properDSN has already been set up in an earlier step.The following PHP code snippet uses the ODBC module to connect to an <strong>Oracle</strong>data source, and it should be similar to code in the existing solution.When migrated to connect to SQL Server, the connection string will reflect thechanges that follow.Change all embedded SQL statements to T-SQL.Refer to Chapter 11, "Developing: Applications — <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> adetailed discussion on modifying <strong>Oracle</strong> SQL to be SQL Server-compliant.Table 13.3 is a listing of the ODBC function calls that are used in PHP code to work withdatabases.Table 13.3: ODBC Function Calls in PHPOperation Task ODBC FunctionConnection Open connection odbc_connect()Open persistent connection odbc_pconnect()Close connectionodbc_close()Get connection in<strong>for</strong>mation odbc_data_source()Parsing Prepare statement odbc_prepare()Cursor Get cursor name odbc_cursor()Execution Execute statement odbc_execute()Prepare and execute odbc_exec()odbc_do()

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 249Operation Task ODBC FunctionFetching Fetch row odbc_fetch_row()odbc_fetch_array()odbc_fetch_into()odbc_fetch_object()Fetch column -Transaction Management Commit odbc_commit()Rollbackodbc_rollback()Error Handling Error Checking odbc_error()Get last error odbc_errormsq()Others Name of result column odbc_field_name()Name of table column odbc_columns()Size of result column odbc_field_len()Datatype of result column odbc_field_type()Number of rows effected odbc_num_rows()Number of columns odbc_num_fields()returnedCommon Function Translation IssuesThough SQL Server and <strong>Oracle</strong> share a great deal of functionality, some databaseoperations differ. This section discusses some of the differences between coding withPHP extensions <strong>for</strong> <strong>Oracle</strong> and SQL Server.Handling TransactionsThe <strong>Oracle</strong> PHP extension module supports transactions using the following functioncalls:● ora_commit()● ora_commitoff()● ora_commiton()● ora_rollback()The OCI PHP extension module supports transactions using the following function calls.● OCICommit()● OCIRollBack()MSSQL API does not provide commit or rollback functions. These functions can beachieved using the following example code:// Here $db is a PHP variable <strong>for</strong> connection object//To begin transaction$sql = "begin tran";$result= mssql_query($sql,$db);//To commit transaction$sql = "commit tran";$result = mssql_query($sql,$db);

250 Developing: Applications — <strong>Migrating</strong> PHP//To rollback transaction$sql = "rollback tran";$result = mssql_query($sql,$db);<strong>Migrating</strong> Cursors$conn=mssql_connect("myhost","user","pwd");mssql_select_db("hr",$conn);// create the select statement$sqlquery="SELECT companyName FROM Customers;";// activate the query and retrieve the result set$results= mssql_query($sqlquery);// Do a row fetch from the result set <strong>for</strong> displaywhile ($row=mssql_fetch_array($results)){echo $row['companyName']."\n";}<strong>Oracle</strong> requires using cursors with SELECT statements, regardless of the number ofrows requested from the database. In SQL Server, a SELECT statement that is notdisclosed on a cursor returns rows to the client as a default result set. This is an efficientway to return data to a client application.When porting a PL/SQL procedure from <strong>Oracle</strong>, first determine whether cursors areneeded to per<strong>for</strong>m the same function in Transact-SQL. If the cursor is used only to returna set of rows to the client application, use a non-cursor SELECT statement in Transact-local procedure variables, use cursors in Transact-SQL.Unlike <strong>Oracle</strong> and OCI8 (which have methods <strong>for</strong> explicit use of cursors), MSSQL usesSQL to return a default result set. If the cursor is used to load data a row at a time intoimplicit cursors. Functions such as mssql_query() and mssql_execute() associate ahandle to the returned result, which can be traversed similar to an explicit cursor. Thefollowing code shows the use of result set to achieve the same functionality as that of acursor.SQL Server cursors may also be used <strong>for</strong> one of the following reasons:● Updateable cursors● Scrollable, read-only cursorsNote ODBC Cursor Library cursors build on top of default result sets. Be sure to fetchto the end of the result set quickly to free up locks.When you use server cursors, use SQLExtendedFetch to fetch in blocks of rowsinstead of a single row at a time. This is the same thing as array-type fetching in<strong>Oracle</strong>. This saves on round-trip fetches to the server. For more in<strong>for</strong>mation onSQLExtendedFetch, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/odbc/htm/odbcsqlextendedfetch.asp.Use result sets when you think it will fetch all rows at one time, but use server cursorswhenyou know a result set would not fetch all rows at once.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 251Connection PoolingWhile PHP does not offer connection pooling, persistent <strong>Oracle</strong> connections canopened with the following API function calls.● <strong>Oracle</strong> API: ora_plogon()● OCI8 API: ociPLogon()To interoperate with SQL Server, these functions should be replaced by one of thefollowing functions, depending upon the API used:● ODBC API: odbc_pconnect()● MSSQL API: mssql_pconnect()Unlike connection pooling, a persistent connection is local to a process and cannot beshared between different processes.Stored ProceduresSto red procedures can be handled by the MSSQL API as well as the ORA and OCI8APIs. The following example shows sample stored procedures using MSSQL calls.// Create Query <strong>for</strong> Stored Procedure In Code// Stored procedure name: CustOrdersDetail from Northwind database$stmt = mssql_init("CustOrdersDetail",$conn);bemssql_select_db("Northwind", $conn);// Parameter values$orderid = 1;// Binding parameter value to stored proceduremssql_bind($stmt, "@OrderID", $orderid, SQLINT4);// Execute SQL Statement & Capture Results$result = mssql_execute($stmt);// Fetch return data and place into array <strong>for</strong> accesswhile($row = mssql_fetch_array($result)){// Assign Variables$unitprice = $row["UnitPrice"];echo "Unit Price" . $unitprice;$quantity = $row["Quantity"];echo "Quantity" . $quantity;$discount = $row["Discount"];echo "Discount" . $discount;$price = $row["ExtendedPrice"];echo "Price" . $price;}

252 Developing: Applications — <strong>Migrating</strong> PHPScenario 2: Porting the Application to Win32Because PHP is a cross-plat<strong>for</strong>m language, porting applications from a UNIXenvironment to Windows is not much more complex than the steps required <strong>for</strong>interoperation. The strategy, steps, and actual changes required are very similar to thosediscussed <strong>for</strong> interoperation. The only additional step is installing PHP and the applicationcode in the Windows environment.Case 1: Porting a PHP Application using ORA FunctionsMost of the following steps are covered in more detail in the "Case 1: Interoperating aPHP Application Using ORA Functions" section of Scenario 1. To port the application using ORA functions, follow these common steps:1. Install PHP on target Windows server.For more in<strong>for</strong>mation on installing PHP, refer tohttp://uk2.php.net/manual/en/install.php.2. Install SQL Server libraries.Instead of the FreeTDS libraries, the Windows-based libraries offered by Microsoftin SQL Client Tools can be installed on the system where PHP is installed. TheClient Tools can be installed from the MS SQL Server CD or by copyingntwdblib.dll from \winnt\system32 on the server to \winnt\system32 on the targetWindows server. However, copying ntwdblib.dll will only provide access.Configuration of the client will require installation of all the tools.3. Compile PHP to use the MSSQL module.4. Enable MSSQL functions in php.ini.5. Verify the installation using phpinfo().6. Transport source code to target server.7. Modify the application's source code to reflect the MSSQL API instead of ORAfunctions..Case 2: Porting a PHP Application Using OCI8 FunctionsMost of the steps needed to migrate this application are discussed in more detail in the"Case 2: Interoperating a PHP Application Using OC18 Functions" section of Scenario 1.The following steps are required to migrate PHP applications to Windows using OC18functions. To port the application using OCI8 functions, follow these common steps:1. Install PHP on target Windows server.2. Install SQL Server libraries from SQL Client Tools.3. Compile PHP to use the MSSQL module.4. Enable MSSQL functions in php.ini.5. Verify the installation using phpinfo().6. Transport the source code to the target Windows server.7. Modify the application code to reflect the MSSQL API instead of OCI functions.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 253Case 3: Porting a PHP Application Using ODBC FunctionsMost of the steps listed as follows are discussed in more detail in the "Case 3:Interoperating a PHP Application Using ODBC Functions" section of scenario 1. Thefollowing steps are required to migrate PHP applications to Windows using ODBCfunctions. To port the application using ODBC functions, follow these common steps:1. Install PHP on target Windows server.2. Install ODBC software.For installation instructions, refer tohttp://support.microsoft.com/default.aspx?scid=kb;en-us;313008.3. Install the SQL Server driver.In addition to the drivers mentioned <strong>for</strong> interoperation, the Microsoft ODBC driver<strong>for</strong> SQL Server may also be used. This driver is available along with theSQL Server client CD. Installation instructions are available athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/howtosql/ht_install_029l.asp.4. Compile PHP to use ODBC in the php.ini file.5. Configure the DSN to connect with the SQL Server database.6. Check the connection using command line utilities.7. Transport the source code to the target Windows environment.8. Modify the application source code to reflect the MSSQL API.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 25514Developing: Applications —<strong>Migrating</strong> JavaIntroduction and GoalsThis chapter contains a detailed discussion of changes that must be made to Javaapplications when the database is migrated from <strong>Oracle</strong> to Microsoft® SQL Server. Atthe conclusi on of this chapter, the Java application should be capable to successfullyconnect to t he SQL Server database that was migrated from <strong>Oracle</strong>. The solution canthen be tested.Java is a po rtable language. The capability <strong>for</strong> the Java programming language tointeract with an RDBMS such as <strong>Oracle</strong> and SQL Server is provided by the JavaDatabase Connectivity (JDBC) API. Applications written in Java can execute SQLstatements, retrieve results, and propagate changes back to the underlying data sourceusing the JDBC API.The combination of the Java plat<strong>for</strong>m and JDBC API allows a program to operate on anumber of plat<strong>for</strong>ms, and with any number of SQL-supported databases, withoutmodifying the source code.When migrating from an <strong>Oracle</strong> to a SQL Server environment, there will still be somealterations made to the application. These basic changes will need to be made whetherthe Java application interoperates with SQL Server from a UNIX environment, or if theJava application is ported to Windows®.As discussed in the "Define the <strong>Solution</strong> Concept" section of Chapter 2, "EnvisioningPhase," there are four different strategies available <strong>for</strong> transitioning applications in an<strong>Oracle</strong> to SQL Server migration project. The strategies are:● Interoperate the application with UNIX● Port or rewrite the application to the Microsoft .NET plat<strong>for</strong>m● Port or rewrite the application to the Microsoft Win32® plat<strong>for</strong>m● Quick p ort using the Microsoft Windows Services <strong>for</strong> UNIX 3.5 plat<strong>for</strong>mBecause of some of the unique characteristics of Java, some of these strategies aremore logical than others. For instance, because Java can be ported to Windows, there isno need to rewrite the application in the .NET framework or <strong>for</strong> the Win32 environment.

256 Developing: Applications — <strong>Migrating</strong> JavaBased on the available migration strategies, two scenarios can be developed to migratethe Java application. These scenarios are:● Scenario 1: Interoperating Java on UNIX with SQL ServerIf the business requirements do not include eliminating the UNIX environment, aninteroperation strategy can be implemented quickly. Few, if any, changes need tobe made to the source code and it may be necessary to install a new driver toallo w the Java application to connect to a SQL Server database. If the migration isper<strong>for</strong>med in phases or <strong>for</strong> multiple applications, interoperation can be used as aninterim step.● Scenario 2: Porting the Application to Win32Java applications can also be ported to run natively on the Windows plat<strong>for</strong>m. Aswith interoperation, few changes need to be made to the source code.Scenario 1: Interoperating Java on UNIX withSQL ServerInteroperation between a UNIX-based Java application and a SQL Server database ispossible because of the availability of a driver that interfaces between thesetechnologies. The JDBC driver provides the cross-RDBMS connectivity needed.Case 1: Interoperating a Java Application Using the JDBCDriverBecause of the construction of the JDBC API, which exposes a common set of methodsthat are not affected by the change of source database, this type of migration is usually asimple process. Most changes made relate to the connectivity. To interoperate a Java application using the existing JDBC driver, followthese steps:1. Evaluate the current driver.Be<strong>for</strong>e beginning the migration process, evaluate the existing JDBC driver that is inuse and its capability to operate with SQL Server. Some considerations include:● Will the current JDBC driver interoperate with SQL Server? If this in<strong>for</strong>mation isnot known, check with the vendor. Sun Microsystems also maintains adatabase of SQL Server compliant JDBC drivers. For more in<strong>for</strong>mation, referto http://servlet.java.sun.com/products/jdbc/drivers.● If the current JDBC driver will interoperate with SQL Server, what are theper<strong>for</strong>mance characteristics of the driver in the SQL Server environment?Try to per<strong>for</strong>m prototype tests of the driver to ensure that the level ofper<strong>for</strong>mance is acceptable.● What features of the driver are utilized by the Java application, and arethese supported <strong>for</strong> SQL Server? For more in<strong>for</strong>mation on specific Javaextensions used by your JDBC driver, refer to your vendor documentation.● What type of JDBC driver is required (Type 1, 2, 3, 4)?If a new driver is needed, there are several different JDBC driverscommercially available. Each has slightly different features and characteristics.Some commonly used JDBC drivers include:● JSQLConnect from JNetDirect, which is available athttp://www.jnetdirect.com/products.php?op=jsqlconnect.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 257●SQL Server 2000 Driver <strong>for</strong> JDBC. Microsoft offers this native driver whichwill work on both UNIX and Windows. This driver is available athttp://www.microsoft.com/downloads/details.aspx?FamilyId=07287B11-0502-461A-B138-2AA54BFDC03A&displaylang=en.2. Determine how the application connects to the data source. Connections can beachieved using the DriverManager class or with a datasource implementation.●If connectivity is obtained using the DriverManager class, two changes areneeded to connect with the SQL Server database. These changes are:● Loading the JDBC driver● Making the connectionThe following example shows these changes:// Loading the driverClass.<strong>for</strong>Name("DriverClassName");// Making the ConnectionString url = "jdbc:odbc:DSN";String user = "sUser";String password = "sPwd";Connection con = DriverManager.getConnection(url, user, password);//……………//…………// Closing the Connectioncon.close();In this example code, the URL uses the syntaxjdbc::. Using the connection object con, you cancreate JDBC statements and pass them to the RDBMS.●If connectivity is obtained through a datasource, the application server shouldbe appropriately configured.Be<strong>for</strong>e using a datasource object, it must be deployed. The following listdescribes the deployment steps:1. Create an instance of the DataSource class.2. Set the datasource properties.3. Register the datasource with a naming service that uses the Java Namingand Directory Interface (JNDI) API.Datasource deployment is usually per<strong>for</strong>med by the system administrator.A JDBC driver that supports JDBC 2.0 API will provide different types ofdatasource implementations which can be used <strong>for</strong> connection pooling anddistributed transactions.To obtain connectivity, the Java application per<strong>for</strong>ms a lookup of thelogicalName. This in<strong>for</strong>mation can be retrieved by passing the user nameand password through the getConnection() method. An example of thismethod is presented as follows:Context ctx = new InitialContext();DataSource ds = (DataSource)ctx.lookup("jdbc/dbServer");Connection con = ds.getConnection("sUser", "sPwd");3. Configure the application server.If third-party JDBC drivers are used to connect to SQL Server, the drivers must beset in the CLASSPATH variable so the driver classes can be loaded. The JDBC

258 Developing: Applications — <strong>Migrating</strong> Javadriver installed <strong>for</strong> SQL Server will install a driver jar file, which contains driverclasses <strong>for</strong> the database interaction. If the jar file is missing in the classpath, thenthe application will flag a 'class not found' exception.Based on the application's architecture, the CLASSPATH must be set. The syntaxof this setting can vary between applications, servlets, JSPs, EJBs, and applets.a. For applications run directly from the operating system prompt, make sure thatthe driver can be found in the system's CLASSPATH. This can be per<strong>for</strong>medby moving the file to its original location, which is already listed in theclasspath, or adding the driver's current location to the CLASSPATH.b. For applications run within the IDE, the driver classpath has to be set in thevendor's IDE classpath. Refer to your vendor’s IDE documentation.c. For servlets and JSPs run within a servlet/JSP engine such as Tomcat, theclasspath can be set in the vendor's classpath setup screens or by copying thedriver jar file into the LIB folder of the engine’s installation.d. For EJBs, the JDBC driver jar file should also be set in the EJB vendor'sclasspath.e. For applets that run within a Web browser, copy the JDBC driver jar to theWeb server root and specify the driver jar file in the applet’s HTML archive tab.The following HTML code example shows this option used on an applet tag.4. If the SQL statements passed to the JDBC methods use any <strong>Oracle</strong>-specificsyntax, then these items will need to be updated to reflect T-SQL syntax. Migrationof PL/SQL to T-SQL is covered in detail in Chapter 11, "Developing: Applications— <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL."5. The metadata in<strong>for</strong>mation returned by the metadata methods should refer toSQL Server and the new JDBC Driver.To discover in<strong>for</strong>mation about a database, a DatabaseMetaData object must beobtained. ResultSetMetaData provides in<strong>for</strong>mation about the ResultSet, such asnumber of columns returned, an individual column's suggested display size,column names, and column types. If any of these metadata are used in theapplication, they have to be validated <strong>for</strong> integrity of the return values.To discover in<strong>for</strong>mation about a database, a DatabaseMetaData object must beobtained. The getMetaData method on the Connection object returns aDatabaseMetaData object.DatabaseMetaData dbmd = con.getMetaData();ResultSetMetaData provides in<strong>for</strong>mation about the ResultSet. Use thegetMetaData method on the resultSet to get the ResultSetMetaData.ResultSetMetaData rsmd = rs.getMetaData();6. After the application changes are complete, create a new release build and fullytest the application.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 259Scenario 2 —Porting the Application to Win32Java is portable, so when the application is migrated to Windows, the Java languagefeatures remain the same. Changes should be minimal. Most of the changes listed in thefollowing procedure are similar to those per<strong>for</strong>med under the interoperation scenariodescribed in the "Scenario 1: Interoperating Java on UNIX with SQL Server " sectionearlier in this chapter. To port the application to Win32, follow these common steps:1. Install Java on the Windows server.If the migration path includes porting the Java application to the Windowsenvironment, then the Java application server should be installed on Windows.Ensure that the hardware satisfies the installation prerequisites <strong>for</strong> the applicationserver.2. Determine if the existing JDBC driver will per<strong>for</strong>m the needed functions, or if a newJDBC driver will be required.3. Configure the application server <strong>for</strong> use with Windows. Update the path andclasspath in<strong>for</strong>mation.4. Test the installation of the application server using the test utility provided with theapplication server.5. Determine how the application connects to the data source.SQL Server has two types of authentication, Windows authentication andSQL Server authentication. When the application exists on the UNIX plat<strong>for</strong>m, theWindows authentication method is not possible without the installation of additionalsoftware such as the Vintela Authentication Services (VAS) product from Vintela(http://www.vintela.com/products/vas/). However, with the application migrated tothe Windows plat<strong>for</strong>m, the Windows authentication feature of SQL Server can betaken advantage of.Windows authentication is specified using the connection propertytrustedAuthentication. The property may be set in either a driver managerconnection string or a datasource. There is no need to specify the user andpassword properties when using trusted authentication.Windows authentication can be used by the JDBC clients on Windows only.6. Move the Java code from UNIX to Windows. All the files and folders which theJava application interacts with should be migrated to Windows. Make sure that thepaths in the Java application and the configuration files point to the correspondingfolders in the Windows file system. If the Java application uses any native codewritten in other languages, then that code also has to be migrated to Windows.7. <strong>Oracle</strong>-specific SQL and stored programs will need to be rewritten in T-SQLsyntax. Migration of PL/SQL to T-SQL is covered in detail in Chapter 11,"Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL."8. The metadata in<strong>for</strong>mation returned by the metadata methods should refer toSQL Server and the new JDBC Driver.9. After the application changes are complete, create a new release build and fullytest the application.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 26115Developing: Applications —<strong>Migrating</strong> PythonIntroduction and GoalsThis chapter contains a detailed discussion of changes that must be made to existingPython applications to work with Microsoft® SQL Server. At the conclusion of thischapter, the Python application should be capable to successfully connect to theSQL Server database that was migrated from <strong>Oracle</strong>. The solution can then be tested.As discussed in the "Define the <strong>Solution</strong> Concept" section of Chapter 2, "EnvisioningPhase," there are four different strategies available <strong>for</strong> transitioning applications in an<strong>Oracle</strong> to SQL Server migration project. The strategies are:● Interoperate the application with UNIX● Port or rewrite the application to the Microsoft .NET plat<strong>for</strong>m● Port or rewrite the application to Microsoft Win32® Plat<strong>for</strong>m● Quick port using the Microsoft Windows® Services <strong>for</strong> UNIX 3.5 plat<strong>for</strong>mPyt hon is a portable, plat<strong>for</strong>m-independent, and general-purpose language with support<strong>for</strong> writing database client applications. Database capabilities are modularized, and theycan be augmented through the use of additional APIs.Python database modules that are based on the Database API (DB-API) specificationcan be used to access relational databases, including SQL Server and <strong>Oracle</strong>. As long asthe data base module used to access the <strong>Oracle</strong> database adheres to the DB-APIspecification, porting to SQL Server is straight<strong>for</strong>ward and can be done with minimalchanges. If the existing database drivers do not meet DB-API specifications, the driverwill need to be replaced and configured.Because of the cross-plat<strong>for</strong>m capabilities and the use of modular database drivers,some of the migration strategies are more feasible than others. For example, becausePython can be ported to Windows, there is no need to rewrite the application in the .NETframework or <strong>for</strong> the Win32 environment. Also, because the application can run within theWindows environment, a quick port using Windows Services <strong>for</strong> UNIX is not necessary inmost cases.Based on the available migration strategies, two scenarios can be developed to migratethe Python application. These scenarios include:

262 Developing: Applications — <strong>Migrating</strong> Python●●Scenario 1: Interoperating Python on UNIX with SQL ServerIf the business requirements do not include eliminating the UNIX environment, aninteroperation strategy can be implemented quickly. Few changes need to bemade to the source code, and installing a new driver allows the Python applicationto connect to a SQL Server database. Interoperation can also be used as aninterim step, if the migration is per<strong>for</strong>med in phases.Scenario 2: Port the Python Application to Win32Python applications can also be ported to run natively on the Windows plat<strong>for</strong>m. Aswith interoperation, few changes need to be made to the source code. Thesechanges are usually related to connectivity issues.Note: If your Python applications use UNIX system calls extensively (such asfrequently calling exec), porting them to Windows Services <strong>for</strong> UNIX/Interix may be asuitable option because Interix has more support <strong>for</strong> the desired system calls. Chapter2, " Envisioning Phase," provides a more detailed discussion of when choosingWindows Services <strong>for</strong> UNIX would be more appropriate when moving to a Windowsbasedplat<strong>for</strong>m.You will need the following to implement this option (porting Python applications toSFU/SQL Server):● A port of Python <strong>for</strong> interix has been made available by Interop Systems and canbe downloaded from http://www.interopsystems.com/tools/warehouse.htm.● A c onnectivity driver to the SQL Server database. This is provided by the port ofFreeTDS on Interix and is downloadable from Interop Systems athttp://www.interopsystems .com/tools/db.htm. FreeTDS provides two connectivityoptions <strong>for</strong> the Python applications to connect to the SQL Server database. One isa library called CTlib, The other is an ODBC driver.● If you chose the CTLib option <strong>for</strong> your database connectivity driver, you will needthe Sybase Connectivity Module <strong>for</strong> your Python application to make appropriatecalls to CTLib. The source code <strong>for</strong> this Sybase Connectivity Module can obtainfrom Object Craft at http://www.object-craft.com.au/projects/sybase/ . This solutionis not available pre-compiled from Interop Systems but is a simple port <strong>for</strong> a UNIXdeveloper.● If you chose ODBC <strong>for</strong> your database connectivity, you will need an additionalinterface <strong>for</strong> the Python application to make ODBC calls. This is available as acommercial package called mxODBC and can be obtained fromhttp://www.egenix.com.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 263● If you use the ODBC driver, you will also need an ODBC driver manager. Twodifferent ODBC driver managers iODBC and unixODBC are available <strong>for</strong>Windows Services <strong>for</strong> UNIX fromhttp://www.interopsystems.com/tools/warehouse.htm.This technology option (porting Python applications to SFU), however, has not beenfully tested as a part of development of this solution and there<strong>for</strong>e has not beendetailed further.Scenario 1: Interoperating Python on UNIX withSQL ServerTwo com mon modules used <strong>for</strong> connecting a Python application to an <strong>Oracle</strong> database inthe UNIX environment are:● DC<strong>Oracle</strong>2● mxODBCDC<strong>Oracle</strong>2 (http://www.zope.org/Products/DC<strong>Oracle</strong>/) does not support SQL Server, butmxODBC ( http://www.egenix.com/) supports the ODBC interface and can be used withSQL Server. If the existing application uses DC<strong>Oracle</strong>2, this interface will need to bereplaced to allow connectivity with SQL Server.Because ODBC is not database-specific, only minor modifications are needed to connectto the migrated database.Case 1: Interoperating Using the mxODBC Module To interoperate a Python-based application using DC<strong>Oracle</strong>2 module withSQL Server, follow these steps:Note that these steps assume that a DC<strong>Oracle</strong>2 module will be replaced with the mxODBCmodule.1. Install the ODBC driver.In order <strong>for</strong> mxODBC to connect to SQL Server, an ODBC driver manager must beinstalled. Two available driver managers are:● iODBC, available at http://www.iodbc.org/.● DataDirect ODBC <strong>for</strong> UNIX Plat<strong>for</strong>ms, available athttp://www.datadirect.com/techzone/use_case/odbc-unix-sqlservermain/index.ssp.For detailed installation instructions, refer tohttp://www.datadirect.com/techzone/use_case/odbc-unix-sqlserverinstall/index.ssp.2. Install the mxODBC module based on the Python version being used.For installation instructions, refer to http://www.egenix.com/files/python/mxODBC-Zope-DA.html#Installation.3. Configure the ODBC driver to work with mxODBC through the driver manager.4. Create a SQL Server data source.To function, ODBC needs a data source to connect to the database. The DataSource Name (DSN) is generally defined in an odbc.ini file that is used by thedriver ma nager. The DSN is used by the driver manager to load the ODBC driver.iODBC offers a graphical user interface to set up the DSN. Complete instructionsare available at http://www.iodbc.org/index.php?page=docs/odbcstory.

264 Developing: Applications — <strong>Migrating</strong> PythonThe DSN can also be configured by manually modifying the odbc.ini file. Thefollowing example file uses a SQL Server DSN.[ODBC Data Sources]SS_ HR_DB=Sample MS SQLServer[SS_HR_DB]Driver=/opt/odbc/lib/mxODBC.soDescription=SQL Server 2000Database=hrappLogonID=davebPassword=cougarAddress=win2kdbp1,14335. Test the connectivity.iODBC contains a utility named odbctest which can be used to test DSN entriesand interact with the database by connecting and issuing queries directly withoutany code.The mxODBC package consists of a test script that can also be used to verify thedatabase connectivity. To per<strong>for</strong>m the test, execute the following command:python mx/ODBC/Misc/test.py6. Modify the application to use mxODBC instead of the existing DC<strong>Oracle</strong>2 API.Note The examples in this section use the iODBC driver. Syntax may vary slightlybased on the ODBC driver that is used in your solution.There are several, minor changes that may need to be made to the existing Pythonapplication to allow connectivity with the SQL Server database. These commonissues that should be modified include:● Import statementsThe import statement, generally found at the head of the application code,should be modified to include the new database module.If the application currently uses the DC<strong>Oracle</strong>2 module, the import statement isas follows:●import DC<strong>Oracle</strong>2This entry should be modified to allow <strong>for</strong> the mxODBC module. The importstatement should be changed as follows:import mx.ODBC.iODBCConnection objectsThe connection object will also need to be modified to point to the new datasource. The current entry should be similar to the following example:db = DC<strong>Oracle</strong>2.Connect('scott/tiger@orahrdb')This entry should be modified to reflect the new data source. In the followingexample, the DriverConnect() API is used to pass additional in<strong>for</strong>mation toSQL Server.db = mx.ODBC.iODBC.DriverConnect('DSN=sqlserverDSN;UID=scott;PWD=tiger')This iODBC string will have to be modified based on the driver manager in use.There are other connection methods, such as ODBC() and connect(), whichare also supported by mxODBC. The advantage with DriverConnect() is that itallows more configuration in<strong>for</strong>mation, such as the log file name, to be passedas part of the connection string.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 265●Cursor ExecutionChange the cursor object execute() and executemany() method calls to use aquestion mark (?) <strong>for</strong> parameters instead of numeric parameters (:1) or namedparameters (:column_name). The following example should be similar to yourexisting Python code being used with <strong>Oracle</strong>.c = db.cursor()custId = "ALFKI"c.execute("Select * from customers where customerID = :1", custId)...id = "123"name = "Bill"desc = "CoffeeShop"●c.execute("insert into categories " + \" (categoryid, categoryName, description)" + \"values (:cid,:cname,:cdesc)" \,cid = id , cname = name ,cdesc= desc \)The code should be modified <strong>for</strong> use with SQL Server. In the following code,note that numeric and named parameters have been replaced.c= db.cursor()custId = "ALFKI"c.execute("Select * from customers where customerID = ?",(custId,))...id = "123"name = "Bill"desc = "CoffeeShop"c.execute("insert into categories" + \" (categoryid, categoryName, description)" + \"values (?,?,?)" \,(id, name, desc) \)Cursors — multiple executionsThe executemany() function is used with DC<strong>Oracle</strong>2 to per<strong>for</strong>m multiple insertswith a single call by passing a list of parameters. For example,cursor.executemany("insert into inventoryinfo values (:1,:2)",\[('Bill','Dallas'),('Bob','Atlanta'),('David','Chicago'), \('Ann','Miami'),('Fin','Detroit'),('Paul','Dallas'),\('Scott','Dallas'),('Mike','Dallas'),('Leigh','Dallas')])For using multiple cursors on a connection to SQL Server, use thesetconnectoption() method to set the SQL.CURSOR_TYPE toSQL.CURSOR_DYNAMIC as shown as follows and replace the parameterspecification style in the executemany() call:# Connect to the databasedb = mx.ODBC.iODBC.DriverConnect('DSN=sqlserverDSN;UID=scott;PWD=tiger'# Set SQL Server connection optionDB.setconnectoption(SQL.CURSOR_TYPE, SQL.CURSOR_DYNAMIC)cursor = db.cursor ()cursor.executemany("insert into inventoryinfo values (?,?)",\[('Bill','Dallas'),('Bob','Atlanta'),('David','Chicago'), \

266 Developing: Applications — <strong>Migrating</strong> Python●('Ann','Miami'),('Fin','Detroit'),('Paul','Dallas'),\('Scott','Dallas'),('Mike','Dallas'),('Leigh','Dallas')])Stored ProceduresThe DB API 2.0 callProc() method <strong>for</strong> executing stored procedures is notimplemented in mxODBC. To overcome this deficiency, a stored procedurecan be executed similar to a SQL statement using one of the execute methods.However, a requirement in this case is that the stored procedure returns someresult. All calls to callProc() need to change to use cursor.execute, as shownin the following example:c.execute("{call proc_name(?,?)}", (1,2)})7. Change all embedded SQL statements to T-SQL.This is a step common to all migrations. Refer to Chapter 11, "Developing:Applications — <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL," <strong>for</strong> a detailed discussion onmodifying <strong>Oracle</strong> SQL to be SQL Server-compliant.Scenario 2: Port the Python Application to Win32Because Python is a cross-plat<strong>for</strong>m language, porting applications from a UNIXenvironment to Windows is not much more complex than the steps required <strong>for</strong>interoperation. The API used in the discussion on porting to the Windows environment isthe mxODBC. The strategy, steps, and actual changes required are very similar to thosediscussed <strong>for</strong> interoperation. Zope offers an ADO adapter <strong>for</strong> SQL Server on theWindows plat<strong>for</strong>m which can give better per<strong>for</strong>mance than the use of ODBC. Details onthis can be obtained from http://zope.org/Members/freiser/ZADODA.Case 1: Porting a Python Application using mxODBCMost of the following steps are covered in more detail in the "Case 1: InteroperatingUsing the mxODBC Module" section discussed in scenario 1. To port the application to Windows, follow these steps:1. Download Python <strong>for</strong> Windows from http://www.python.org.2. Install Python on Windows.3. Add the Python folder to the Windows CLASSPATH environment variable.4. Install the appropriate mxODBC <strong>for</strong> the version of Python installed.5. Create an ODBC DSN <strong>for</strong> the target database.Create an ODBC data source to connect to SQL Server. After the DSN is created,a Python application using mxODBC can connect to SQL Server and run queries.6. Transport source code to the target server.7. Update the application code.If your application uses DC<strong>Oracle</strong>2, then the application changes required will besimilar to those discussed in the "Scenario 1: Interoperating Python on UNIX withSQL Server" section earlier in this chapter. Some variations based on the Windowsenvironment include the import statement and the connection object as shown inthe following examples.● The import statement should be changed from:import DC<strong>Oracle</strong>2toimport mx.ODBC.Windows

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 267●The connection object must be initialized as in the following example:db = mx.ODBC.Windows.DriverConnect('DSN=sqlserverDS')Note This DSN uses Windows Authentication Mode to connect to SQL Server.8. Change all embedded SQL statements to T-SQL.This is a step common to all migrations. Refer to Chapter 11, "Developing:Applications— <strong>Migrating</strong> <strong>Oracle</strong> SQL and PL/SQL" <strong>for</strong> a detailed discussion onmodifying <strong>Oracle</strong> SQL to be SQL Server-compliant.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 26916Developing: Applications —<strong>Migrating</strong> <strong>Oracle</strong> Pro*CIntroduction and GoalsThir d generation languages (3GL) such as C and C++ do not have the capability tointerface with databases. Databases can only communicate using the SQL fourthgeneration language (4GL). Using embedded SQL allows a database to interface directlywith the 3GL languages. Pro*C is <strong>Oracle</strong>'s proprietary interface to the C language whichpermits the use of embedded SQL.As discussed in the "Define the <strong>Solution</strong> Concept" section of Chapter 2, "EnvisioningPhase," there are four different strategies available <strong>for</strong> transitioning applications in an<strong>Oracle</strong> to Microsoft® SQL Server migration project. The strategies are:● Interoperate the application with UNIX● Port or rewrite the application to the Microsoft .NET plat<strong>for</strong>m● Port or rewrite the application to the Microsoft Win32® plat<strong>for</strong>m● Quick port using the Microsoft Windows® Services <strong>for</strong> UNIX 3.5 plat<strong>for</strong>mBecause Pro*C is specific to <strong>Oracle</strong>, migration strategies are limited. Interoperation andporting cannot be utilized because no methods exist that allow Pro*C to communicatewith SQL Server. A complete rewrite is the only option.This chapter focuses on the preferred scenario that can be used in Pro*C applicationmigrations: Scenario 1: Rewriting the application to the .NET plat<strong>for</strong>m.Rewriting an application is a challenging endeavor because a one-to-one mapping fromthe source environment to the target environment is very difficult to achieve. When anapplication is rewritten, there is always a risk that some functionality from the originalapplication may be lost during the transition. Commonly, Pro*C programs are proceduraland do not have a graphical user interface. <strong>Migrating</strong> procedural code is easier thanmigrating GUI-based applications. Extensive testing needs to be per<strong>for</strong>med on therewritten application to ensure that all of the business logic and functionality hasaccurately been recreated.This chapter only discusses the trans<strong>for</strong>mation that needs to occur to the most commondatabase-related components when rewriting a Pro*C application <strong>for</strong> the .NETenvironment. A comprehensive study of the entire rewrite is beyond the scope of thisguidance.

270 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Pro*CUnderstanding the TechnologyPro*C is available on the Windows plat<strong>for</strong>m. Un<strong>for</strong>tunately, there are no methodsavailable to allow Pro*C code to interface with SQL Server. Microsoft offers a productsimilar to Pro*C called Embedded SQL <strong>for</strong> C (ESQL/ C) which allows Transact-SQLstatements to be embedded in C language programs. ESQL/C can be used as the targetlanguage <strong>for</strong> rewriting Pro*C programs because of its close resemblance to Pro*C.However, using this language is not recommended because Microsoft no longer developsthis product, and future versions of SQL Server will not support ESQL/C.Visual Basic .NET is recommended <strong>for</strong> rewriting the application. Visual Basic .NETprovides a robust scripting language and can easily be interfaced with SQL Server.When migrating the database from <strong>Oracle</strong> to SQL Server, the Pro* C code and itsinteractions with <strong>Oracle</strong> should be examined to ensure that the functions can berecreated in the rewritten application.Understanding Pro*CBe<strong>for</strong>e the application can be rewritten, you must evaluate the functionality currentlyprovided by the Pro*C application. While the computational and business logic isprovided by the host C language, Pro*C provides the syntax to implement the databasetransactions. The embedded SQL in Pro*C offers the following functionality that will haveto be migrated:● Connect to and maintain a connection to <strong>Oracle</strong> database.● Declare, open, and use cursors to manipulate data.● Interact with <strong>Oracle</strong> databases through SQL statements.● Provide mechanisms (host variables) to interface between the host code and thedatabase code.● Close any open cursors.● Handle any database exceptions.● Close the connection to the database.Each of these functions will need to be recreated in the new application. Pro*C is mostlyused as an imperative programming language and is used <strong>for</strong> constructing programswhich involve computation. The target programming environment should haveprogramming capabilities and features that are similar to those of C/C++ and alsointerface with SQL Server <strong>for</strong> retrieving and manipulating data. The GUI capabilities willnot be discussed in this guide.Understanding .NET and ADO.NETThe Microsoft .NET Framework provides a programming infrastructure <strong>for</strong> building,deploying, and operating applications and services. When working with databases,ADO.NET is a key component.ADO.NET is a set of libraries included with the Microsoft .NET Framework that enablescommunication with various data stores from .NET applications. The ADO.NET librariesinclude classes <strong>for</strong> connecting to a data source, submitting queries, and processingresults. ADO.NET provides the tools to efficiently implement data access andfunctionality provided by Pro*C. Data access in ADO.NET relies on the following twoentities:● DataSet

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 271●Data providerDataSetThe DataSet is a copy of the data retrieved from the database cached in memory. Datacan be loaded into a DataSet from any valid data source, such as a SQL Serverdatabase, or an XML file. The DataSet persists in memory, and the data therein can bemanipulated and updated independent of the database. When appropriate, the DataSetcan then be used <strong>for</strong> updating the database.Data ProviderA data provider <strong>for</strong>ms the link between the Visual Basic .NET program and the database.A data provider is not a single component; rather it is a set of related components thatwork together to provide data in an efficient, per<strong>for</strong>mance-driven manner.Two data providers are available <strong>for</strong> Visual Basic .NET. The SQL Server Data Provider isdesigned specifically to work with SQL Server 7 or later, and the OLE DB Data Provider,which can also connect to other types of databases. Each data provider consists ofversions of the following generic component classes:● The Connection object provides the connection to the database.● The Command object executes a command against a data source. It can executenon-query commands, such as INSERT, UPDATE, or DELETE, or return aDataReader with the results of a SELECT command.● The DataReader object provides a <strong>for</strong>ward-only, read-only, connected recordset.● The DataAdapter object populates a disconnected DataSet or DataTable with dataand per<strong>for</strong>ms updates.The following classes are also offered: Transaction, CommandBuilder, Parameter,Exception, Error, and ClientPermission.For more in<strong>for</strong>mation on data provider components, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconusingadonetproviderstoa ccessdata.asp.Even though the syntax and use of the functions differ, ADO.NET provides equivalentdatabase functions <strong>for</strong> SQL Server. It is important to ensure that these functions aretranslated to the new environment during the rewriting process.Scenario 1: Rewriting Pro*C to the .NET Plat<strong>for</strong>mRewriting the application <strong>for</strong> Windows makes use of native SQL Server APIs, ADO.NET,Microsoft ActiveX Data Objects (ADO), or Open Database Connectivity (ODBC) runningnatively in the Windows subsystem. Rewriting the application can result in a more stableand integrated configuration after the project is complete.Case 1: Rewrite the Application using Visual Basic.NETVisual Basic.NET provides all the functionality of the C programming language as well asseveral interfaces to SQL Server databases to execute SQL statements. This scenariodescribes how to rewrite a Pro*C application with Visual Basic .NET.The figure that follows shows a graphical representation of howthe Pro*C code willmigrate over to Visual Basic .NET during the rewrite.

272 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Pro*CFigure 16.1Database access in Pro*C and Visual Basic .NETEach function that currently resides in Pro*C code will need to be rewritten, from the userinterface to the database connection. There are two options available to connect to theSQL Server data source from the .NET framework.These options are:● The SQL Server .NET Data Provider is implemented in the SQLClient namespace.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 273● The OLE DB provider is in the OLE DB namespace. There are OLE DB providers<strong>for</strong> both <strong>Oracle</strong> and SQL Server. To rewrite an application using Visual Basic .NET, follow these steps:For more in<strong>for</strong>mation on data access services available with ADO.NET, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/cpguide/html/cpconaccessingdatawithadonet.asp.The examples used in these procedures are based on SQL Server .NET DataProvider andDataReader objects. If an OLE DB provider is used, there may be slight variations to thefollowing steps.1. Install the .NET Framework SDK and redistribution. The SDK contains thereso urces <strong>for</strong> building, testing, and deploying .NET Framework applications. Foraccess to the latest SDK, refer tohttp://msdn.microsoft.com/netfram ework/downloads/updates/default.aspx.The Microsoft Visual Basic .NET software is required <strong>for</strong> programming theapplication. For more in<strong>for</strong>mation, refer tohttp ://www.microsoft.com/downloads/details.aspx?FamilyID=dd6ec730-fd9a-4e36-8552-8accc4cd8fb3&DisplayLang=en.At t his point, it is assumed that you have all the components in place to write a VB.NET application using the SQL Server .NET DataProvider. It is also assumed thatthe migrated SQL Server database is in place.For access to several references <strong>for</strong> creating Windows <strong>for</strong>ms applications, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconCreatingWindowsFormsApplicat ions.asp.2. Rewrite connectivity statements within application code.● In Pro*C, database open and close statements are similar to the followingexample:/* assign username and password to host variables */strcpy(username.arr,"SCOTT");username.len=strlen(username.arr);strcpy(password.arr,"TIGER");password.len=strlen(password.arr);/* execute connect statement */EXEC SQL CONNECT :username IDENTIFIED BY :password;●/* execute close statements */EXEC SQL COMMIT WORK RELEASE;These same functions can be recreated using ADO.NET. Here are examplesof the same functions as written <strong>for</strong> .NET.' declare a connection objectDim cn As New SqlConnection' define a connection stringDim strConn As String'This is the connection stringstrConn = "Data Source=(local)\DataSourceName;" & _"Initial Catalog=databaseName;" & _"Trusted_Connection=Yes;"' instantiate connection object

274 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Pro*Ccn = SqlConnection(strConn)' open connectionscn.Open()' close connectionscn.Close()For more details on SqlConnection, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/cpref/html/frlrfsystemdatasqlclientsqlconnectionclasstopic.asp3. Rewrite the queries and cursor functions.Pro*C uses embedded SQL to store the output of a query statement in a cursorfrom which rows can be fetched. Visual Basic.NET does not support cursors;instead, it uses several other methods <strong>for</strong> retrieving data sets from SQL queries.One of these data retrieval methods is the DataReader object, which is aligh tweight object that is read-only and, hence, ideal <strong>for</strong> queries. The following linkprovides access to more in<strong>for</strong>mation on retrieving data using DataReader object:http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpcontheadonetdatareader.asp.● Here are some common cursor operations encountered in Pro*C applications:Defining a cursor:●EXEC SQL DECLARE cust_cursor FORSELECT CustomerID, CompanyName FROM Customers;Opening the cursor:EXEC SQL OPEN cust_cursor;Fetching rows using the cursor:<strong>for</strong> (;;){EXEC SQL WHENEVER NOT FOUND DO break;EXEC SQL FETCH cust_cursor INTO :customerid, :companyname;printf("CustomerID: %s – CompanyName: %s\n", customerid,companyname);}Closing the cursor:EXEC SQL CLOSE cust_cursor;Although SQL Server does not support cursors, equivalent functions can becreated using ADO.NET:Defining the query:strSQL = "SELECT CustomerID, CompanyName FROM Customers"Creating a command object:Dim cmd As New SqlCommand(strSQL, cn)Creating a data reader object:Dim rdr As SqlDataReader = cmd.ExecuteReader()Displaying the data reader result set:While rdr.Read()Console.WriteLine(rdr("CustomerID") & " – " & rdr("CompanyName"))End WhileDo While rdr.Read()Console.WriteLine(rdr.GetInt32(0) & " " & _“ rdr.GetString(1) & " " & rdr.GetFloat(2))

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 275For more in<strong>for</strong>mation on implementing a DataReader, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconimplementingdatareader.asp.4. Rewrite the embedded DML statementsThe embedded DML is used to insert, update, and delete data. The SqlCommandobject can be used to per<strong>for</strong>m these SQL operations. The DataAdapter andDataSet objects are required <strong>for</strong> executing DML and stored procedures. Migrationof these operations is shown in the following examples:● The DML operations using Pro*C:Executing an INSERT DML statement:LoopClosing the data reader object:rdr.Close()●EXEC SQL INSERT INTO Customer VALUES (:newcompanyname, :customerid);Executing an UPDATE DML statement:EXEC SQL UPDATE CustomerSET CompanyName = :newcompanynameWHERE CustomerID = 'ACME';Executing a DELETE DML statement:EXEC SQL DELETE FROM CustomerWHERE CustomerID = 'ACME';For each of the DML operations shown, the equivalent operations can beper<strong>for</strong>med using ADO.NET:Executing an INSERT DML statement:Dim strSQL As StringstrSQL = " INSERT INTO Customer VALUES " & _" (@newcompanyname,@customerid)"Dim cmd As New SqlCommand(strSQL, cn)Dim param1, param2 As SqlParameterParam1 = cmd.Parameters.Add("@newcompanyname",SqlDbType.VarChar, 10)Param2 = cmd.Parameters.Add("@customerid", SqlDbType.NChar, 5)Param1.Value = ”COMPANY1"Param1.Value = "VALUE1"cmd.ExecuteNonQuery()Executing an UPDATE DML statement:Dim strSQL As StringstrSQL = "UPDATE Customer SET CompanyName = @newcompanyname " & _"WHERE CustomerID = 'ACME'"Dim cmd As New SqlCommand(strSQL, cn)Dim param1 As SqlParameterParam1 = cmd.Parameters.Add("@newcompanyname", SqlDbType.VarChar, 10)Param1.Value = "NewName"Dim InsertRecordsAffected As Integer = cmd.ExecuteNonQuery()Executing a DELETE DML statement:Dim strSQL As StringstrSQL = " DELETE FROM Customer WHERE CustomerID = 'ACME'"Dim cmd As New SqlCommand(strSQL, cn)Dim InsertRecordsAffected As Integer = cmd.ExecuteNonQuery()

276 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Pro*C5. Rewrite Transaction Management operations●The Transaction Management operations in Pro*C are:Beginning a transaction:EXEC SQL SET TRANSACTION READ ONLY;Committing a transaction:EXEC SQL COMMIT WORK RELEASE;Setting a savepoint:EXEC SQL SAVEPOINT save_point;Rollback a transaction:EXEC SQL ROLLBACK WORK RELEASE;Rollback to a savepoint:EXEC SQL ROLLBACK TO SAVEPOINT save_point;● Transaction Management in ADO.NETChanges are made through the DataSet object. The Update method is used <strong>for</strong>copying the changes made to the dataset back to the database which implicitlycommits the changes.6. Rewrite calls to stored procedures.● Stored procedures are executed in Pro*C using the syntax shown in thefollowing example. In this example, the host variables represent IN or OUTparameters.EXEC SQL EXECUTE●BEGINGET_ROOM_DETAILS(:HotelId, :RoomType, :AvailableRooms,:StandardRate);END;END-EXEC;Stored procedure calls in ADO.NET: SqlCommand objects can be used to callSQL Server and MSDE stored procedures. The SqlCommand object exposesa CommandType property that can be used to help simplify the code to callstored procedures. Set SqlCommand object’s CommandText property to thestored procedure name, and the CommandType property to StoredProcedure,and then call the stored procedure, as shown in the following code:Dim strConn As StringstrConn = "Data Source=(local)\NetSDK;Initial Catalog=Northwind;" & _"Trusted_Connection=Yes;"Dim cn As New SqlConnection(strConn)Dim cmd As New SqlCommand("GET_ROOM_DETAILS", cn)cmd.CommandType = CommandType.StoredProcedureDim param As SqlParameterparam = cmd.Parameters.Add("@HotelId", SqlDbType.NChar, 5)param.Value = "HOTEL1"………………cn.Open()Dim rdr As SqlDataReader = cmd.ExecuteReader()Do While rdr.Read()Console.WriteLine(rdr("OrderID"))…………Loop

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 277rdr.Close()A more detailed discussion on using stored procedures in Visual Basic.NET isavailable at http://msdn.microsoft.com/library/default.asp?url=/library/enus/dnadvnet/html/vbnet09102002.asp.7. Rewrite exception handling.●●There are two ways to handle <strong>Oracle</strong> errors in Pro*C:●●SQLEXECembedded statements. The syntax is:SQL WHENEVER [condition] [action];Checking error codes in SQLCAThe generic syntax isif ( sqlca.sqlcode == [a value i.e., -1] ){Handler code}Exception handling in Visual Basic .NETUse a Try block to add exception handling to a block of code. Add Catchblocks, as necessary, to trap individual exceptions. The .NET runtime handlesCatch blocks in order, looking <strong>for</strong> an "is a" match against the current exception.It uses the first block it finds that matches. You can nest Try blocks, making iteasy to effectively push and pop exception-handling states. Add a Finally blockto your Try block to run code unconditionally, regardless of whether an erroroccurs or not.You can create your own exception classes that inherit from the baseexception class (or any class that inherits from that class) to add your ownfunctionality:Try' Code that throws exceptionsCatch E As OverflowException' Catch a specific exceptionCatch E As Exception' Catch the generic exceptionsFinally' Execute some cleanup codeEnd TryA more detailed discussion of error handling in VB.NET can be found athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/dnvbdev01/html/vb01f1.asp.8. Change all embedded SQL statements to T-SQL. This is a step common to allmigrations. Refer to Chapter 11, "Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong>SQL and PL/SQL," <strong>for</strong> a detailed discussion on modifying <strong>Oracle</strong> SQL to beSQL Server-compliant.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 27917Developing: Applications —<strong>Migrating</strong> <strong>Oracle</strong> FormsIntroduction and Goals<strong>Oracle</strong> Forms are applications built using <strong>Oracle</strong> Developer, a Rapid ApplicationDevelopment (RAD) environment available from <strong>Oracle</strong>. <strong>Oracle</strong> Forms-basedapplications can retrieve and manipulate data in <strong>Oracle</strong> databases. These <strong>for</strong>ms can alsobe deployed across the Web.It is not possible to modify an <strong>Oracle</strong> Forms application <strong>for</strong> interoperation with aMicrosoft® SQL Server database, and it is recommended that applications of this typeare rewritten. Microsoft Visual Basic® .NET is an ideal choice <strong>for</strong> rewriting an <strong>Oracle</strong>Forms application because it is very similar in nature to <strong>Oracle</strong> Developer, both in termsof the development tools and wizards, as well as the end product itself.This chapter is <strong>for</strong> developers who want to migrate their <strong>Oracle</strong> Forms application runningon an <strong>Oracle</strong> database to Visual Basic .NET running on SQL Server. The tools,processes, and techniques required <strong>for</strong> a successful conversion are described.In this guide, the <strong>Oracle</strong> Forms application is first analyzed <strong>for</strong> its components, and thena similar analysis of the Visual Basic .NET application environment is conducted.Strategies <strong>for</strong> migrating from <strong>Oracle</strong> Forms to Visual Basic .NET are then examined. Adetailed discussion on how to per<strong>for</strong>m the migration is beyond the scope of this guide.The goal of this chapter is to provide a blueprint <strong>for</strong> per<strong>for</strong>ming the migration.Migration Approach<strong>Migrating</strong> an <strong>Oracle</strong> Forms application to Visual Basic .NET is complex, and thetreatment of the subject here should be seen as a design sketch from which a detailedanalysis and plans <strong>for</strong> an application migration can be made.The basic approach is feasible <strong>for</strong> the following two reasons:1. <strong>Oracle</strong> Forms and Visual Basic user interfaces share many common elements.2. The <strong>Oracle</strong> Forms Designer is capable to generate Visual Basic code.The <strong>for</strong>m is the basis <strong>for</strong> the user interface (UI) in both <strong>Oracle</strong> Forms and Visual Basic.The <strong>for</strong>m is graphical in nature and is used to present data and accept user input, and the<strong>for</strong>m can contain elements which are both graphical and non-graphical in nature. <strong>Oracle</strong>

280 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> FormsForms and Visual Basic have several common elements between them. However, theirorganization, naming, and properties differ.Figure 17.1 illustrates how different components of <strong>Oracle</strong> Forms map to components inVisual Basic .NET.Figure 17.1Mapping of <strong>Oracle</strong> Forms to Visual Basic .NET WinFormThis diagram shows how all the high-level components of an <strong>Oracle</strong> Forms applicationmap to components in Visual Basic .NET. This mapping serves as a convenient guide <strong>for</strong>the work to be done and also helps maintain the logical composition of the application.The mapping also helps avoid introducing too many unintended side effects, such asfiring of triggers at the wrong time and complicating the migration. This diagram is used inthis chapter todocument the source <strong>Oracle</strong> Forms application, define the targetVisual Basic .NET application, and plan <strong>for</strong> per<strong>for</strong>ming the migration.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 281Examining <strong>Oracle</strong> Forms<strong>Oracle</strong> Forms applications are <strong>Oracle</strong> database optimized transactional applications builtusing the tools provided by <strong>Oracle</strong>'s Developer Suite. <strong>Oracle</strong> Forms Builder, a part of<strong>Oracle</strong> Developer suite, enables you to quickly and easily create database <strong>for</strong>ms andbusiness logic. The development is done using wizards, drag-and-drop components, andbuilt-in functions. A visual editor can be used to refine the <strong>for</strong>ms with graphics and othercomponents. The coding language is PL/SQL. A client/server Forms application can runon the Web with very little or no modification.Like most GUI applications, an <strong>Oracle</strong> Forms application is composed of two parts: theapplication logic and the user interface. <strong>Oracle</strong> Forms maintains this separationthroughout its design. Hence the Forms Runtime is the same in both the two-tier andthree-tier architectures.An understanding of the basic concepts and components that make up a <strong>for</strong>m isimportant to planning an application migration. Figure 17.2 shows a simplified view of the<strong>Oracle</strong> Forms environment.Figure 17.2High-level organization of <strong>Oracle</strong> Forms componentsAn <strong>Oracle</strong> Forms application is an organization of items. The organization of the itemshas two perspectives: that of the developer, called the <strong>for</strong>m view; and that of the user,called the visual (or presentation) view. In the <strong>for</strong>m view, the items are organized intological blocks and have no visual structure. The visual structure is provided byconstructing the visual view where items are placed on a canvas and presented to theuser in windows. It is very important to maintain the same visual view when an <strong>Oracle</strong>Forms application is migrated. The Visual Basic .NET developers need to look at thevisual view to understand how many screen layouts they need in Visual Basic .NET.Each item in a canvas will correspond to one control in .NET.The migration should be attempted by creating two models: one is based on the<strong>for</strong>mview, called the Form Model; and the other is based on the visual view, called the VisualModel. Figure 17.1 shows the <strong>for</strong>m view of the mapping from <strong>Oracle</strong> Forms toVisual Basic .NET. The equivalent visual view is shown in Figure 17.3.

282 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> FormsFigure 17.3Mapping of visual view of <strong>Oracle</strong> Forms to Visual Basic .NETThe <strong>for</strong>m view is used by the developer to access the business logic and the dataaccess. The visual view is used to build the user interface.Note Providing a complete description of how to trans<strong>for</strong>m every item and every pieceof code from an <strong>Oracle</strong> Forms application to a Visual Basic .NET application is beyondthe scope of this guide.In this section, the entire <strong>Oracle</strong> Forms application is examined, with an emphasis onunderstanding the database-related components.An <strong>Oracle</strong> Forms application is built using components called modules. The following fourtypes of modules are visible when a <strong>for</strong>m application is opened up in <strong>Oracle</strong> FormsBuilder:1. Object Library2. PL/SQL Library3. Form Module4. Menu ModuleFigure 17.4 shows the details of an <strong>Oracle</strong> Forms application as seen in the OwnershipView using <strong>Oracle</strong> Forms Builder. This tool will be employed in documenting the currentapplication.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 283Figure 17.4An <strong>Oracle</strong> Form as visible in <strong>Oracle</strong> Forms BuilderAn application can be built using multiple <strong>for</strong>ms, menus, and library modules. The <strong>Oracle</strong>Forms Builder can be used to browse the component model and understand the modulesand their characteristics so that the Forms Model can be built. The elements offered bythese modules account <strong>for</strong> the capabilities, features, and functioning of the applicationand should be the focus of the developer involved in migrating an application.

284 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> FormsTable 17.1 is a compilation of the files that make up an <strong>Oracle</strong> Forms application.Table 17.1: <strong>Oracle</strong> Forms File ExtensionsModule Extension CharacteristicForm .fmb Form design file.fmx.fmtForm executable runfileForm text export fileMenu .mmb Menu design file.mmxMenu executable runfile.mmt Menu text export filePL/SQL Library .pll PL/SQL library design file (can also be executed— contains both source and executable code).plxPL/SQL library executable runfile (contains nosource code).pldPL/SQL library text export fileObject Library .olb Object library design file.oltObject library text export file<strong>Oracle</strong> Forms Builder can be used to view all the components in a Forms application byopening the <strong>for</strong>m and clicking View, and then Show PL/SQL only.Object LibraryThe object-oriented programming concept of reusing code is implemented in <strong>Oracle</strong>Forms by the object library and PL/SQL library modules. The Object library containsreusable objects and the PL/SQL library contains reusable code. Hence, these areexamined first <strong>for</strong> a migration.The Object library is a collection of <strong>for</strong>ms objects that can be used in other <strong>for</strong>m, menu, orlibrary modules. The Object Library is used to store, maintain, and distribute standard<strong>for</strong>ms objects, which can then be reused across the entire application. They also helpconserve runtime memory and encourage reuse. The objects in an Object Library arecommonly organized as folders. The organization may be by type of item or byapplication functional area.A good example of the use of an object library is a control block used to enter complexsearch criteria in a query-only <strong>for</strong>m. This control block is then used in multiple <strong>for</strong>ms.<strong>Oracle</strong> Forms Builder allows creation of a subclassed version of a library object <strong>for</strong> reusein any desired module. To be able to tell whether an object is subclassed or not, look atthe subclass in<strong>for</strong>mation property of the data block.The object-oriented features of Visual Basic .NET allow you to model library objectinheritance closely to maintainthe same structure. The object library can be viewed as aDLL.PL/SQL LibraryThe PL/SQL library contains reusable code invoked by other <strong>for</strong>m, menu, or librarymodules. The code, also called a program unit, can be user-named functions,procedures, or packages. The program unit is stored and executed on the client. Theprogram units are not <strong>for</strong> database-related code alone. They may contain purely businesslogic. For example, the code could be used to check the validity of a user input in a <strong>for</strong>m.Any SQL contained in these program units is passed to the database.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 285Libraries make all the PL/SQL code available to the <strong>for</strong>m without being part of the <strong>for</strong>m.The libraries are loaded dynamically. Multiple <strong>for</strong>ms can attach the same PL/SQL library.Table 17.1 identifies the files that are related to the PL/SQLneeds to be migrated.Form ModuleLibrary that contain code thatA <strong>for</strong>m (or <strong>for</strong>m module) is the main component that anchors an application and providesthe necessary code to interact with the datasource and the user interface. The underlyingdatabase data is reflected in multiple items, including fields, check boxes, and radiogroups. A <strong>for</strong>m is logically organized into blocks.BlocksA block is a container <strong>for</strong> a group of related items such as text boxes, lists, and buttons.The block itself does not have a visual representation.<strong>Oracle</strong> Forms Builder consists of two main types of blocks. These are:1. Data blocks2. Control blocksThese two kinds of blocks are very different from each other. The data block serves as abridge to the underlying data and provides an abstraction <strong>for</strong> how the data is reached.The control blocks are more like programming units that can organize controls into logicalgroups <strong>for</strong>ming part of the same user interface navigation cycle. Whether a block is adata block or a control block can be determined by verifying the Database Data Blockproperty <strong>for</strong> the block. It is a data block if the setting is "Yes" and a control block if thesetting is "No."Data BlockA data block can be associated with a specific database table (or a view), a storedprocedure, a FROM clause query, or a transactional triggers. By default, the associationbetween a data block and the database allows <strong>for</strong> automatic access and manipulation ofdata in the database. Triggers are used when a data block needs access to tables notdirectly associated with it (non-base tables).Various relationships can exist between data blocks and their underlying base tables. Acommon relationship is the master-detail relationship where each row in the master tablecorresponds to one or more rows in the detail table. The master-detail relationshipallows the primary key and <strong>for</strong>eign key values to be linked across data blocks. <strong>Oracle</strong>Forms Builder automatically generates the objects and the PL/SQL code needed tosupport the master-detail relationships when these blocks are built using the Data BlockWizard.

286 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> FormsFigure 17.5 shows the different components that make up a master-detail block ascreated by the Data Block Wizard.Figure 17.5Code generated by <strong>Oracle</strong> Forms Builder Data Block Wizard in creating a master-detail blockBy capturing a query on a table, a block can also be designed to show one or morerecords at a time. These are called single-record blocks or multi-record blocks,respectively.Visual Basic .NET developers can use <strong>Oracle</strong> Forms Builder to look at the generatedcode to find out about the relationships between the blocks. For example, in Figure 17. 5,code in the ON-POPULATE-DETAILS trigger on the DEPT block suggests that it is themaster block of the EMP block.In Visual Basic .NET, the equivalent of an <strong>Oracle</strong> Form data block is a Dataset into whichdata can be read from the database, and on the visual side, a DataGrid control bound tothe Dataset will be capable to display the data. Dataset is just one option. In addition tothe Dataset, ADO.NET offers DataReader <strong>for</strong> read-only data access.Additional properties convey the association between a data block and a table, such asthe WHERE clause and ORDER BY clause that will be used to create SQL <strong>for</strong> theVisual Basic .NET Dataset. The Insert Allowed, Update Allowed, and Delete Allowedproperties will tell the Visual Basic .NET developer whether the block will insert, update,or delete any records.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 287Figure 17.6 shows all the properties of a data block.Figure 17.6Properties of a data blockControl BlockThe second type of block is the control block. The items in a control block are notassociated with the database, and its items do not relate to any columns within anydatabase table. The items in a control block are called control items. For example,buttons in a module can initiate certain actions and can be logically grouped in a controlblock. The control block is only a logical grouping and the physical or visual placementmay differ. It is also a mechanism to segregate the control block items from the items thatare dependent on the database. Control items are used to per<strong>for</strong>m functions, such asaccepting input from the user and displaying calculated values and look values.Program UnitsProgram units are part of <strong>for</strong>ms modules and they contain named procedures, functions,or packages. The program units are similar to the program units created in the librariesbut are local to the <strong>for</strong>m in which they are created. They are stored and executed on theclient with any embedded SQL passed to the database <strong>for</strong> processing. If this codecontains database interactions, then it needs to be converted to T-SQL. If it contains onlynon-database related code, then it needs to be converted to its equivalent inVisual Basic .NET.TriggersThe trigger object is a PL/SQL block executed on an event. Triggers can be owned by the<strong>for</strong>m module, a data block, or an item, depending upon their scope.

288 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> FormsIf this code contains database interactions, then it needs to be converted to T-SQL. If itcontains only non-database code, then it needs to be converted to its equivalent inVisual Basic .NET.When a trigger is activated, it executes the code it contains. Each trigger’s name defineswhat event will fire it; <strong>for</strong> example, a WHEN-BUTTON-PRESSED trigger executes itscode each time the user clicks the button to which the trigger is attached.A trigger can be replaced by an equivalent event in Visual Basic .NET. The equivalent ofan <strong>Oracle</strong> Forms WHEN-BUTTON_PRESSED trigger in Visual Basic .NET is the Clickevent procedure. Double-click the page Button control in design view to open the codebehind the page and create a Click event procedure.List of Values (LOV)A LOV is a pop-up window that provides the user with a selection of values. The valuescan be static or populated by querying the database. LOVs are populated using columnsreturned by record groups. Check the Record Group property of the LOV <strong>for</strong> the recordgroup which is used to provide values. Visual Basic .NET offers pop-up windows that canbe programmed to display a list of values obtained by the DataReader.Record GroupsA record group is a data structure in the <strong>for</strong>m module which behaves like a local table <strong>for</strong>data retrieved from the databases. Record groups are a way to share small List of Values(LOV). The values can be retrieved using a query or a subprogram. Look into theproperty Record Group Query to see the SQL statement upon which the record group isbased. A record group can be replaced by DataReader in Visual Basic .NET.Menu ModuleThe menu module consists of a hierarchy of menus. Each menu consists of the items thatcan be selected. Menu modules are usually attached to <strong>for</strong>m modules. Every <strong>for</strong>mmodule has a default menu that includes the commands <strong>for</strong> all basic databaseoperations, such as insert, update, delete, and query. Visual Basic .NET offers a widerange of functionality involving menus.After inserting, updating, or deleting records from an <strong>Oracle</strong> <strong>for</strong>m, changes are not madein the underlying database until the changes are committed with a save command. Whilerewriting this module in Visual Basic .NET, it is important to know whether inserts,updates, and deletes are permitted on a data block. The data block properties of InsertAllowed, Update Allowed, and Delete Allowed determine these.Any item in a menu can also be referenced through PL/SQL code to enable/disable menuitems, attach commands to menu items, initialize check or radio menu items, and changemenu start-up code.Windows and CanvasesWindows and canvases <strong>for</strong>m the basis <strong>for</strong> the visual presentation of the <strong>for</strong>m. The visualmodel is built by looking at the windows and canvases through Form Builder. Thedeveloper can then create an identical representation in Visual Basic .NET based on thevisual model using <strong>for</strong>ms.<strong>Oracle</strong> Forms has two types of windows: document windows (the main application areas)and dialog windows (messages and other actions).The end user interacts with theapplication using these windows. In addition to incorporating all the functionality in theoriginal application, it is also important to maintain the general look and feel of theapplication.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 289The document window is composed of work areas called canvases where visual objectssuch as graphics and items are arranged. Several canvases can be located in a <strong>for</strong>mmodule. All canvases may appear in a single window (by default) or spread acrossmultiple windows (to view simultaneously).From the start, a new document window or dialog has a relationship with a <strong>for</strong>m in whichrelationships to blocks tie the visual representation together with the underlying databasedata. Figure 17.7 shows a window which displays the master-detail view of the data. TheDept part is the header and the Employees part is the detail.Figure 17.7Sample application windowFramesA frame is a visual object found on a canvas. Frames are used to arrange items in termsof blocks. The frame defines visual characteristics such as margins, offsets, anddistances between items. Frames may also be defined in the Object Library to en<strong>for</strong>cestandards across the application. The equivalent of frames in Visual Basic .NET is thepanel.ItemItems are interface objects that present the data values to the users. Items also enablethe user to interact with the <strong>for</strong>m. The type of interaction varies according to the type ofitem. Visual Basic .NET offers a wide range of equivalents <strong>for</strong> the <strong>for</strong>m items calledcontrols.The type of an item can be examined by locating the Item Type property of the item.Items have both a visual representation and a <strong>for</strong>ms representation (code) and willappear in both models. However, the properties captured in each of the models will differ.Only the common items, such as text item, check box, and radio groups, which could bedependent on the database are discussed here. For each of the items, the visual andfunctional characteristics are attached to the visual model and the logical characteristicsare captured in the <strong>for</strong>m model. For example, the height, width, font size, and <strong>for</strong>matmas k are the visual characteristics. The database item (table and column) that is used topopulate the text item is the <strong>for</strong>m characteristic.Text ItemText items allow <strong>for</strong> text to be displayed and manipulated. Text items are called by thename TextBox in Visual Basic .NET. When examining text items, Visual Basic .NETdevelopers need to determine whether this item corresponds to a column in a databasetabl e by looking at the Database Item property. If so, it needs to be tied to a dataset orother data source in Visual Basic .NET. The name of the text item is not necessarily thesame as the name of the database column. Look at the Column Name property <strong>for</strong> thename of database column.

290 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> FormsCheck Box ItemA check box provides the user with a Boolean control that has just two values, such astrue and false, or on and off. The check box values can be set by fetching from thedatabase. When creating the equivalent Check Box control, Visual Basic .NETdevelopers need to look at the following three properties of a check box item: ValueWhen Checked, Value When Unchecked, and Check Box Mapping of Other Values.Radio Group ItemA radio group provides the user with a fixed set of options that are mutually exclusive,Radio group item values can also be set using database columns. Under the radiobutton, the developer should look at the Radio Button Value property <strong>for</strong> the valueassigned to the button. In Visual Basic .NET the radio group can be replaced by acombination of GroupBox and RadioButtons.ButtonsButtons are interface items that can display list of values, commit data in a <strong>for</strong>m, querythe database, or invoke PL/SQL blocks. The WHEN-BUTTON-PRESSED trigger holdsthe code <strong>for</strong> these actions. Buttons are also found in Visual Basic .NET.Understanding Visual Basic .NETVisu al Basic.NET offers Windows® Forms (WinForms) Designer, which is very similar innatu re to <strong>Oracle</strong> Forms Builder. The product of the Windows Forms Designer is aWindows-based <strong>for</strong>m application that is similar in nature to an <strong>Oracle</strong> Forms application.Forms are the fundamental elements of the application on which controls (same as itemsin <strong>Oracle</strong> Forms) can be placed <strong>for</strong> user interaction. As in <strong>Oracle</strong> Forms, menus andtoolbars provide a structure <strong>for</strong> the user to control the application. For readers who areunfamiliar with VB.NET, there is a lot of in-depth technical in<strong>for</strong>mation available athttp://msdn.microsoft.com/vbasic/using/If the conversion of the <strong>for</strong>ms is done correctly, then the WinForm is simply thepresentation layer with all of the database access logic and rules put into a businessobject layer. The conversion to a Web Form solution, as a result, only requiresassociating the appropriate Web server control to an object holding the data retrievedfrom the business object layer.The controls on a <strong>for</strong>m simply provide an interface to the event-driven model that is theequ ivalent of the triggers system in <strong>Oracle</strong> Forms. As changes are made to textbox input,the pressing of buttons, or the selection of items in a list, additional code is triggered (see"Triggers" in the "Form Module" section earlier in this chapter). The code is in the <strong>for</strong>m ofsubroutines that handle the call from the raised event to provide some specific action.The PL/SQL routines will map to these subroutines. The action is typically defined as analgorithm or a business rule. In most applications, the business rules extract in<strong>for</strong>mationfrom the database.A summary of the entire array of controls in WinForms is available athttp://msdn.microsoft.com/library/en-us/vbcon/html/vboriControlsForWinForms.asp.The .NET Framework is so extensible that numerous Independent Software Vendors(ISVs) have created unique controls or have enhanced the functions in existing .NETcon trols. Developers themselves can generate their own controls <strong>for</strong> personal needs.Man y of the most common controls emulate functionality that has been used in visual<strong>for</strong>m s <strong>for</strong> years, whether in classic Visual Basic, Delphi, or <strong>Oracle</strong>. One of the mostbeneficial properties of most controls is the capability to bind them to data sources.Data

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 291sources do not have to be ADO.NET objects. Sources can come from arrays and othercollection-type objects.Scenario 1: Rewriting to Visual Basic .NETCon verting from <strong>Oracle</strong> Forms to Visual Basic .NET is non-trivial. There is no tool thatautomates the conversion to VB.NET. In <strong>Oracle</strong> Forms, an application can be separatedinto a visual or presentation component and a code component. This separation makesthe migration easier and is the approach used in this guidance.Two methods are available to convert <strong>Oracle</strong> Forms to Visual Basic.NET:● Case 1: Using <strong>Oracle</strong> Designer● Case 2: Manually Redesigning the applicationCase 1: Using <strong>Oracle</strong> DesignerVisual Basic code is generated from the <strong>Oracle</strong> Form application using the Visual BasicGenerator, which is a function of <strong>Oracle</strong> Designer. The Visual Basic code is thenupgraded to Visual Basic.NET using the guidance available from Microsoft athttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/vbcon/html/vbconupgradingapplicationscreatedinpreviousversionsofvisualbasic.asp.At the time of publication, this method is not perfect. Many manual changes will still needto be made after the automated conversion. Using <strong>Oracle</strong> Designer is still a usefulexe rcise because it provides a valuable template structure of the migrated Visual Basicapplication even though subsequent changes to the code will be necessary.Case 2: Manually Redesigning the ApplicationIn this method, the entire <strong>Oracle</strong> Forms application is documented and the newapplication is built in an orderly fashion. To document and redesign the application, follow these steps:1. Create a list of <strong>for</strong>ms found in the application and note the relationship betweenthem.2. Create two models <strong>for</strong> each <strong>for</strong>m.The first model, which is called the Forms Model, will contain all the <strong>for</strong>ms components. TheForms Model will document the four modules: <strong>for</strong>ms module, menu module, object libraries,and PL/SQL libraries. The second model, called the Visual Model, will document all thelayout-related components: windows, canvases, frames, and items3. Document the Forms Model.Open a <strong>for</strong>m in the Ownership View using <strong>Oracle</strong> Forms Designer and note thecomponents under each module with their hierarchy from module down to items.Per<strong>for</strong>m the following actions:a. Start with documenting all the modules: <strong>for</strong>ms modules, menu modules, objectlibraries, and PL/SQL libraries using Figure 17. 1 as reference.b. For each module, incrementally refine the model with the next level of detailusing multiple passes.c. Document all the supporting components, such as LOVs, record groups, andprogram units, found under the <strong>for</strong>m module.d. Based on the size of the <strong>for</strong>m, submodels or documents may be prepared <strong>for</strong>subsections of the model.

292 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Formse. A block document may be created <strong>for</strong> just the data blocks and control blocks.Use <strong>Oracle</strong> runtime in debug mode to understand the flow. When you run<strong>Oracle</strong> Forms in debug mode, the runtime environment displays the name ofeach trigger when it fires. Operate the <strong>for</strong>m as a user and document the flow ofexecution in the blocks document.f. A procedures document containing a compilation of PL/SQL code or programunit found in triggers, user-named subprograms, packages, PL/SQL-type menuitems, and menu startup code. All places in a <strong>for</strong>m which contained PL/SQLcode can be conveniently viewed by switching the <strong>for</strong>m view to Show PL/SQLOnly. For each program unit, note the existence of SQL or calls to databasestored programs.4. Document the Visual Model.Open the <strong>for</strong>m in the Visual View using <strong>Oracle</strong> Forms Designer and note thecomponents under each module, capturing the hierarchical relationship asshown in Figure 17.3. Document all the visual characteristics <strong>for</strong> each of thecomponents.5. Convert the shared code.Start the migration by converting the shared components that are under the objectlibraries and PL/SQL libraries. While migrating from <strong>Oracle</strong> Forms toVisual Basic .NET, continue to maintain the same logical grouping andorganization of the various <strong>for</strong>ms components, including the shared libraries.In Visual Basic .NET, create a class library project, one each <strong>for</strong> the object librariesand the PL/SQL libraries.● Migrate the PL/SQL libraries.The procedures document contains the required in<strong>for</strong>mation <strong>for</strong> migrating thePL/SQL libraries. For each PL/SQL library, create a Visual Basic .NET class inthe target project. Each program unit in a library can be migrated into methodswith the equivalent functionality.● Migrate the object libraries.The migration of the object libraries can be per<strong>for</strong>med using the Forms Model.For each object library, create a Visual Basic .NET class in the target project.Each object in a library can be migrated into an equivalent method in the class.6.Convert the Visual Model.Create a Visual Basic .NET Windows application project. The goal in this step isonly to build the shell visually identical to the <strong>Oracle</strong> Forms application. In this step,you are concerned with the <strong>for</strong>m and not the function. The functionality will beaddressed in the next step. For example, a DataGrid control will be added to a<strong>for</strong>m in this step while the tasks to connect to SQL Server and access data areper<strong>for</strong>med in the next step.For each window found in the Visual Model, create a <strong>for</strong>m in the project. InVisual Basic .NET, the concept of canvas is handled by the <strong>for</strong>m itself. The framesin the <strong>Oracle</strong> Forms application should be converted to panels inVisual Basic .NET. The items in a frame should be replaced with its equivalentcontrols. Also add the menu controls to match the <strong>Oracle</strong> Forms application.For steps on adding <strong>for</strong>ms to a project, refer tohttp://msdn. microsoft.com/library/default.asp?url=/library/enus/vbcon/html/vbtskadding<strong>for</strong>mtoproject.asp.For more in<strong>for</strong>mation on how to add Windows Forms Controls, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/vbcon/html/vboriwin<strong>for</strong>mscontrols.asp.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 293For more in<strong>for</strong>mation about learning the techniques <strong>for</strong> arranging the variouscontrols on a Windows Form, refer tohttp://msdn.microsoft.com/library/default.asp?url= /library/en-us/vbcon/html/vbcon<strong>for</strong>msdesigner.asp.For guidance on adding menus, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/vbcon/html/vbconwindowsaccessories.asp.7. Convert the Form Model.At this stage, all the pieces are in place to code the business logic and applicationfunctionality. The majority of the work is related to converting the code in theblocks and items, which was documented in the block document. Because analmost one-to-one mapping of the shared libraries and its objects has beenper<strong>for</strong>med, the code in Visual Basic .NET can be written as a parallel to the code inthe source application.a. Start by converting the components, such as control blocks, program units,record groups, LOVs, and triggers that could be tied to multiple controls.b. Code all the data components in the <strong>for</strong>m because these could be possiblyassociated with multiple controls. A detailed account on how to per<strong>for</strong>m this isprovided in the "Adding Data Components to a Windows Form" section later inthis chapter.c. Complete the migration of the data block by adding code to read data and bindthe grid.d. Although the grid is bound to the dataset you created, the dataset itself is notautomatically filled in. Instead, you must fill the dataset by calling a datasclass file in theadapter method. Double-click the page to display the page'Code Editor. In the <strong>for</strong>m's event handler, call the data adapter's Fill method,passing it the dataset you want to populate: SqlDataAdapter1.Fill(dsDept).e. For more details on data binding and Windows Forms, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/vbcon/html/vboriwindows<strong>for</strong>msdataarchitecture.asp.f. The number of lines of code generated by the Data wizard is far in excess ofwhat would be required if using Data Access Application Block (DAAB) <strong>for</strong>.NET.g. Examine every control and add code to the control and its event.h. Achieve the proper flow of execution through navigation rules similar to thatseen when executing the <strong>Oracle</strong> Form application in the debug mode.Adding Data Components to a Windows FormYou do not directly add a dataset to a page. Access to the dataset can be created in oneof several ways. There are two preferred methods. One method is to use the set of visualobjects available in the Toolbox under the Data tab. The other is to take advantage ofthe Microsoft Data Access Application Block <strong>for</strong> .NET.

294 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> FormsUsing the Visual Studio .NET Data WizardsVisual Studio® .NET Data Wizards are ADO.NET code generators <strong>for</strong> creating accessto SQL Server, OLEDB, <strong>Oracle</strong>, and ODBC data solutions. There is a small series of dataobjects needed to generate datasets to sources under ADO.NET. They areDataAdapters, connections, commands, and the datasets themselves. Connectionsprovide the necessary in<strong>for</strong>mation about data sources, authentication, and poolingoptions. Commands define whether the source is queried through stored procedures,direct table access, or through T-SQL Statements. DataAdapters provide a specific pipe<strong>for</strong> accessing data and trans<strong>for</strong>ming it back to the source by creating the Select, Update,Insert, and Delete commands; creating stored procedures; or using existing storedprocedures. DataSets act as the virtual database to the client. To use the wizards to access SQL Server, follow these steps:1. Create the SqlAdapter.From the Toolbox within VS.NET, choose the Data tab and drag theSqlDataAdapter onto the <strong>for</strong>m area. If other data providers are needed, choose theappropriate OLEDB or ODBC Data Adapter. The wizard will start, and aSqlDataAdapter1 object will be created in the Component Tray area beneath the<strong>for</strong>m.2. Reference the connection.The next step of the wizard is to choose from a drop-down list of pre-existingconnections used with VS.NET or to generate a new connection. Clicking NewConnection brings up the DataLink Properties dialog box to create the newconnection object.3. Choose a query type.The wizard then allows the developer to choose between SQL statements orstored procedures. As previously mentioned, it is best to use stored procedureswhen possible.4. Generate the SQL statements, stored procedures, or bind the commands.Depending on the choice in the previous step, the developer will be given theopportunity to provide or create an appropriate SQL statement. Inspecting thePL/SQL code is described earlier in the section "PL/SQL Library."5. Finish the wizard.Now the Component Tray contains both the SqlDataAdapter1 and SqlConnection1objects. The in<strong>for</strong>mation created from the wizard can be viewed in from theProperties window of the designer or by looking at the generated code. TheProperties window of the DataAdapter shows the commands chosen (Delete,Insert, Select, Update) and their respective properties.6. Generate the DataSet.Now that the reference has been made to the source and the pipe has beencreated to work with the source, it is necessary to provide the client with the result.The container necessary <strong>for</strong> this is a dataset. Because the dataset is based on thein<strong>for</strong>mation provided by the adapter, Visual Studio .NET has a wizard to takeadvantage of the in<strong>for</strong>mation stored within the adapter. This is done by rightclickingthe SqlDataAdapter1 inside the component tray, clicking Generatedataset, and then choosing most of the defaults (except when the object isrenamed).Using the Microsoft Data Access Application BlockThe Data Access Application Block encapsulates per<strong>for</strong>mance and resourcemanagement preferred practices <strong>for</strong> accessing SQL Server databases. If used, it willreduce the amount of custom code needed to create, test, and maintain.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 295Specifically, the Data Access Application Block helps you:●●●Call stored procedures or SQL text commands.Specify parameter details.Return SqlDataReader, DataSet or XMLReader objects.Instead of using the wizards (which create numerous references to adapter, command,and connection objects), the Data Access Application Block (DAAB) helps limit thecreation of datasets to as little as one line of code.The Data Access Application Block is available athttp://www.microsoft.com/downloads/details.aspx?FamilyId=F63D1F0A-9877-4A7B-88EC-0426B48DF275&displaylang=en. After downloading, compile the assembly in theVB assembly. It will now be available to be referenced by any Visual Basic .NETapplication.Calling T-SQL Stored Procedures from Windows FormsTo call a stored procedure, you first need to identify the stored procedure, and thencreate a DataReader or DataAdapter object. Each requires a database connection and areference to the stored procedure name through the CommandText property. Next, youset the CommandType property to CommandType.StoredProcedure. Finally, anystored procedure parameters need to be defined <strong>for</strong> input and/or output in a collection ofparameter objects. If the DataReader is used, then the developer must fill the appropriatecontrols by iterating though the collection of rows returned and applying the values to thecontrols. If the DataAdapter is used, then a DataSet must be filled and the controls mustbe bound through the DataSource or DataBinding properties.Testin g the Visual Basic .NET ApplicationThe Visual Basic .NET application is a newly written application instead of a migratedapplication. Even though <strong>Oracle</strong> Forms and Visual Basic are architecturally andfunctionally similar, none of the code is reusable. Hence the application should undergounit testing using a procedure that would be followed <strong>for</strong> new development. However, thisnewly developed Visual Basic .NET application does differ from other new developmentprojects. Remember that the Visual Basic .NET application was designed to mimic the<strong>for</strong>m and function of the <strong>Oracle</strong> Forms application, while most applications are develop edbased on documented requirements.The objective of unit testing is to verify that the user interface closely resembles the<strong>Oracle</strong>Forms application and every component functions correctly. Start by visuallycomparing every frame in th e <strong>Oracle</strong> Forms application to the corresponding window inVisual Basic .NET. Ensure that all panels are present. E nsure that all the controls (items)are accurately presented on the panel. Crosscheck all the visual components against theVisual Model.The event models differ from <strong>Oracle</strong> Forms to Visual Basic .NET. <strong>Oracle</strong> Forms containsa nested hierarchy, with events being fired when moving through the window and itsobjects. These have to be duplicated in Visual Basic . NET. Verify the behavior byper<strong>for</strong>ming a walk-through of the entire application with tracing and debugging enabled.The logs can later be reviewed <strong>for</strong> errors and execution sequences. Visual Basic .NETp rovides a set of methods and properties that help you trace and debug the execution.Interactive debuggers are also available in the Visual Studio .NET SDK.The application should then be tested <strong>for</strong> functionality. Start with testing the menus andthen drilling down window-by-window. Test the functionalityof every control. Use the

296 Developing: Applications — <strong>Migrating</strong> <strong>Oracle</strong> Formssame set of test cases in both applications. Populate the test data in the <strong>for</strong>m and click allthe controls. Verify that all the functional areas and navigation match the old application.Validate that the presentation domain screens are all called by the application.For detailed guidance about all aspects of testing your Visual Basic .NET application andthe available tools, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/vsent7/html/vxoriTestingOptimizing.asp.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 29718Stabilizing PhaseIntroduction and GoalsDuring this phase, the test team verifies that the solution meets the defined quality levelsand that the risk of bugs is eliminated or minimized. Any existing bugs should not affectcritical functionality or per<strong>for</strong>mance. After the solution has been stabilized, it will be ready<strong>for</strong> deployment into the production environment. This chapter highlights the processes ofstabilization as they relate to an <strong>Oracle</strong> on UNIX to Microsoft® SQL Server onWindows® migration project.The main goals <strong>for</strong> the Stabilizing Phase include:● Improve the overall quality of the migrated solution and stabilize <strong>for</strong> release.● Ensure that the solution meets the requirements of the project outlined in theEnvisioning and Planning Phases.● Assemble all of the components of the solution and test the entire system be<strong>for</strong>edeployment.● Complete and validate documentation that is required <strong>for</strong> deployment, operations,and end users.● Evaluate and mitigate the risks involved in releasing the solution <strong>for</strong> deployment.The deliverables produced during the Stabilizing Phase are listed in Table 18.1.Table 18.1: Deliverables <strong>for</strong> the Stabilizing PhaseTask Deliverables OwnerTesting the solution Release versions of source Test Rolecode, executables, releaseversion of scripts, andinstallation documentationTesting the solution Release versions of enduserUser Experience Roletraining materials andoperations documentationTesting the solution Release notes Release ManagementBug tracking and reporting Testing and bug reports Test RolePiloting the solution Pilot Review Release ManagementPiloting the solution Project documents Program ManagementPiloting the solution Sign off document Project team

298 Stabilizing PhaseTestingThe Stabilizing Phase consists of two major activities: testing the solution and piloting thesolution. During testing, the entire ecosystem is evaluated, including the hardware,software, database, connectivity layer, and the application. As a result of the testing,bugs and issues will be tracked and resolved.The second major activity of the Stabilizing Phase pertains to piloting the solution to aselect group consisting of end users, deployment, and operations personnel in theproduction environment. Pilot testing also helps anticipate and resolve any issues thatmay occur during deployment. While piloting the solution is optional, this activity is highlyrecommended because components are deployed into the Windows environment thatwere originally developed <strong>for</strong> another plat<strong>for</strong>m.Testing is an iterative refinement process and is initiated every time there is a change tothe solution (including bug fixes). The occurrence of second and third iterations iscommon in data migrations involving complex data integrity rules. Application testing willvary based on the amount of modifications needed to migrate the solution application.Fo r example, when an application is ported, the code coverage tests may be givenlimited importance because the code base has not changed from the existing application.The test team should accumulate complete knowledge of the software's functionality andthe tests that should be per<strong>for</strong>med to verify them. Often, the original designconsiderations and approach used to create the existing solution are not available to themigration team. This limits the effective knowledge of the test team. Testing should notbe limited only to the parts that the developers have identified as affected by themigration. Changes in the backend database and the environment can manifest itself inunpredictable places.The project team should reuse test cases from the existing solution. If none exist, newtest cases can be created from the business requirements of the existing solution. Testscan then be run against both the source and target systems in the migration project andthe results compared to identify deviations and bugs in the new solution.Logs and audit reports that document any defects associated with the applications needto be created and published to the entire team in conjunction with the tests per<strong>for</strong>med.This is because the source of the bug and the place where it manifests itself may bedifferent. For example, even though a problem may be detected in the application, thesource may be a database configuration or a hardware setting.Each iteration of testing helps make the subsequent iteration more robust and completethan the previous one. This process must continue until an iteration has no exceptions.The number of tests completed and the defect rate are used to measure progress andschedule con<strong>for</strong>mance.A c omprehensive series of tests is key to meeting the goals of the Stabilizing Phase.The se tests provide assurances of the quality and stability of the solution. The followingsections provide in<strong>for</strong>mation about:● Best practices● Preparing <strong>for</strong> testing●●●the <strong>Solution</strong>Types of testingBug tracking and reportingUser Acceptance Testing (UAT) and signoff

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 299This in<strong>for</strong>mation will help you assure the quality and stability of the solution you havedeveloped.Best PracticesWhen testing a solution, two important best practices are clearly defining the successcriteria and approaching testing with a zero-defect mindset.Success CriteriaJudging whether a project has been successful is almost impossible without something tomeasure the project's results against. Success criteria, also called key per<strong>for</strong>manceindicators (KPIs), can be created by defining conditions under which the proposedsolution will achieve its goals. In a migration project, the success criteria can be gaugedby the effectiveness of the new solution. Does it effectively replace the existing solution interms of features, per<strong>for</strong>mance, and function based on results from the test cases?Note Though measured in the Stabilizing Phase, success criteria <strong>for</strong> a project isestablished during the Envisioning and Planning Phases.Zero-defect MindsetThe concept of a zero-defect mindset should encompass the project team's commitmentto p roducing the highest quality product possible. Each member is individuallyresponsible <strong>for</strong> helping achieve the desired level of quality.The zero-defect mindset does not mean that the deployed solution must be flawless;rather, it specifies a predetermined quality bar <strong>for</strong> the deliverables. Oftentimes, theproject schedule will play a determining factor in achieving a zero-defect solution. Insituations where schedule does not allow <strong>for</strong> complete testing, tests should be prioritizedto ensure that all critical functionality is evaluated.In addition, the zero-defect mindset concept should be carried throughout the dynamiclife cycle of the solution. For example, as the database scales over time, additional tuningwill be required to ensure optimum per<strong>for</strong>mance.Preparing <strong>for</strong> TestingPreparation <strong>for</strong> testing involves creating two key items:● Test environment● Bug tracking systemEach of these items is discussed under the following headings.The Test EnvironmentThe development and test plans provide a list of requirements that must be met by thetest environment, and the test environment should be set up according to them. The testenvironment should be completely separate from the production environment. Although itmay not mirror the production environment, it is best if it does.If the development phase is completed, the same hardware and software may be used totest the solution. If the needs <strong>for</strong> the testing environment are more demanding, thenadditional resources may be required. In some situations, it may be necessary to scalethe testing based on the available hardware.In MSF, setting up the test environment starts toward the end of the Planning Phase. Thisis to make sure that a test environment is available to the development team while

300 Stabilizing Phaseindividual components are being developed. However, a full-scale test environment toverify all aspects of an integrated solution will only be required in the Stabilizing Phase.Another consideration of the testing environment is ensuring that it is properly tunedbe<strong>for</strong>e testing commences. Some recommended best practices <strong>for</strong> optimal tuning ofSQL Server running under Windows 2003 include:● Format disk partitions using NTFS 5.0. This file system provides per<strong>for</strong>manceenhancements in Windows 2003.● Configure SQL Server as a stand-alone server. If configured as a domaincontroller,additional resources are utilized, and per<strong>for</strong>mance is reduced.● Set the Application Response setting to optimize <strong>for</strong> background services. Thissetting allows background services to run at a higher priority than <strong>for</strong>egroundapplications and is accessed through the System icon in the Control Panel. Thissetting will improve the per<strong>for</strong>mance of SQL Server.● Turn off additional security auditing. This will reduce I/O activities.● Set the size of PAGEFILE.SYS. Monitor the usage of this swap file used bySQL Server and resize the resources slightly larger than your needs.● Turn off unnecessary services. Review all services and determine which can beturned off.● Turn off unnecessary network protocols.For more in<strong>for</strong>mation on tuning the test environment, refer tohttp://www.microsoft.com/windowsserver2003/evaluation/per<strong>for</strong>mance/tuning.mspx.Bug Tracking <strong>Solution</strong>An effective bug tracking system is needed to make sure that bugs are identified andissues are not dropped until they have been completely resolved. Projects typically haveseveral hundreds or thousands of bugs. It is imperative to have a robust bug trackingsystem in place to address these issues.The bug tracking software <strong>for</strong> the project was selected during the Planning Phase. Usingthis software from the beginning of testing allows all bugs identified through the life cycleof the solution to be tracked in one location. This testing history can also be a usefulreference <strong>for</strong> future releases after the solution has been deployed.Bug categorization is an important consideration during the configuration process of thebug tracking solution. Variables required by the categorization may affect theconfiguration of new and existing bug tracking solutions. These variables include:● Repeatability. This is a variable that measures how repeatable the issue or bug is.Repeatability is the percentage of the time the issue or bug manifests itself.● Visibility. This is a variable that measures the situation or environment that mustbe established be<strong>for</strong>e the issue or bug manifests itself. For example, if the issue orbug occurs only when the user holds down the Shift key while right-clicking themouse and viewing the File menu, the percentage of obscurity is likely to be high.● Severity. This is a variable that measures how much impact the issue or bug willproduce in the solution, in the code, or to the users. For example, a bug thatcauses the application to crash would rank higher than situations that allow theapplication to recover.These three variables are estimated and assigned to each issue or bug by the projectteam and are used to derive the issue or bug priority.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 301Note The priority of a bug can be calculated by using the following <strong>for</strong>mula:(repeatability + visibility) * severity = priorityTypes of TestingOften, the test environment is the first place that all of the separate components (thathave been unit tested in the Development Phase) are combined into a fully functionalversion of the solution. The first task is to ensure that the disparate components of thesolution integrate properly. Next, ensure that the solution per<strong>for</strong>ms as expected. The nextseries of tests check to ensure that the solution will work properly under heavyworkloads. The final set of tests check the solution <strong>for</strong> operational aspects.The following types of testing are useful in an <strong>Oracle</strong> to SQL Server migration:● Integration testing. Does the solution work as a cohesive unit?● Per<strong>for</strong>mance testing. Does the solution meet the baseline requirements?● Stress testing. How does the solution react to stresses and workloads?● Scalability testing. How far will the solution scale? Can the system handleincreased load by adding new hardware as required?● Operational testing. Do the operational aspects of the system per<strong>for</strong>m asexpected?Each of these testing types is described under the following headings.Integration TestingThe first level of testing in the Stabilizing Phase is integration testing, an iterative processin which separate components are combined into larger solutions until the system iscomplete. In integration testing, the focus is on the interfaces between components.Integration testing proves that all areas of the system interface with each other correctlyand that there are no gaps in communication. The final integration test proves that theenti re system works as an integrated unit.Integration testing will also reveal any issues with shared resources. For instance, ifPretty Good Privacy (PGP) encryption is used by more than one application, instead ofhaving a separate key <strong>for</strong> each application, multiple applications could potentially share asingle key.If server consolidation is a business goal <strong>for</strong> this solution, then it has to be per<strong>for</strong>med atthis stage. For more in<strong>for</strong>mation on server consolidation, refer toht tp://www.microsoft.com/downloads/details.aspx?FamilyId=0F70695E-5D0B-4781-8966-84BE43216F9E&displaylang=en.Resolving Integration IssuesThe major reasons issues arise during integration testing are incompatibilities orinconsistencies in the design or implementation of the interfaces between components. Ina migration project, such issues are bound to occur because of interoperation betweenapplications, changes in command usage, and differences in protocols between the twoplat<strong>for</strong>ms. Such issues should be logged and <strong>for</strong>warded to the development team <strong>for</strong>resolution. Another commonly encountered issue is resource shortage because severalcomponents are being assembled <strong>for</strong> the first time. Additional resources, such asprocessor, memory, and storage, should be made available to complete the testing.

302 Stabilizing PhasePer<strong>for</strong>mance TestingPer<strong>for</strong>mance testing involves evaluating how well the solution meets the expectedcriteria. Testing <strong>for</strong> per<strong>for</strong>mance can be further defined by two sub-types:● Application per<strong>for</strong>mance testing● Hardware utilization per<strong>for</strong>mance testingApplication per<strong>for</strong>mance testing in a migration focuses on comparing various speed andefficiency factors between the existing solution and the migrated solution. This ensuresthat the migrated solution complies with the expected level of per<strong>for</strong>mance.These key speed and efficiency factors include:● Throughput. Database throughput measures the total number of transactions thatthe server can handle in a given time frame. Baseline figures from the existingsolution are needed <strong>for</strong> comparison. Per<strong>for</strong>mance testing must be executed usinga workload that represents the type of operations that are most frequentlyper<strong>for</strong>med in the production environment.Note For a detailed discussion of baselines, see Appendix C, "Baselining."●Response time. Response time measures the length of time required to return thefirst row of the result set.The following resources can be used to conduct per<strong>for</strong>mance testing:● Checklist: SQL Server Per<strong>for</strong>mancehttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpag/html/scalenetcheck08.asp.● Windows 2003 Per<strong>for</strong>mance and Scalabilityhttp://www.microsoft.com/windowsserver2003/evaluation/per<strong>for</strong>mance/perfscaling.mspx● Testing toolshttp://msdn.microsoft.com/library/default.asp?url=/library/enus/adminsql/ad_perfmon_1qgj.asp.● CPU Monitorhttp://www.sysinternals.com/ntw2k/freeware/cpumon.shtml● Disk Monitorhttp://www.sysinternals.com/ntw2k/freeware/diskmon.shtmlTesting hardware per<strong>for</strong>mance in a cross-plat<strong>for</strong>m migration is recommended becauseadditional adjustments may need to be made to the proposed solution. There are noreliable benchmarks that can provide equivalency per<strong>for</strong>mance statistics between theUNIX and Windows plat<strong>for</strong>m. The results of benchmarks of the popular TransactionProcessing Per<strong>for</strong>mance Council (http://www.tpc.org/) can be used as a guideline. Youshould ask the assistance of the vendors in per<strong>for</strong>ming lab testing of your solution to getmore accurate numbers on the proposed hardware. This testing validates the hardwarerequirements <strong>for</strong> the solution.While conducting per<strong>for</strong>mance tests, capture data regarding the utilization of resourcessuch as CPU, memory, disk I/O, and network bandwidth. This is important because ifyour testing environment is not the same scale as the production load, then bottlenecksin these resources may not be discovered until deployment. Resource utilization data,captured at various load levels, can be used to draw conclusions about resourcerequirements at production loads.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 303●●Network Monitorhttp://msdn.microsoft.com/library/default.asp?url=/library/enus/netmon/netmon/about_network_monitor_2_0.aspFile Monitorhttp://www.sysinternals.com/ntw2K/source/filemon.shtmlResolving Per<strong>for</strong>mance IssuesPer<strong>for</strong>mance problems can occur because of several reasons: application code,database implementation, hardware configuration, software configuration, or resourceavailability. The testing team should be able to solve configuration and resourceproblems themselves, while issues with the application and database should be loggedand <strong>for</strong>warded to the development team, along with any analysis and supportingevidence <strong>for</strong> resolution. Additional resources may have to be procured to solve resource-related hardware issues.Per<strong>for</strong>mance tuning can be an ongoing series of refinements and improvements. A largeamount of in<strong>for</strong>mation regarding per<strong>for</strong>mance tuning is available. For more in<strong>for</strong>mation,refer to the following resources:● The Data Tier: An Approach to Database Optimizationhttp://www.microsoft.com/resources/documentation/sql/2000/all/reskit/enus/part10/c3361.mspx● Improving SQL Server Per<strong>for</strong>mance includes schemas, queries, indexes,transactions, stored procedures, execution plans and tuning topics.http://msdn.microsoft.com/sql/default.aspx?pull=/library/en-us/dnpag/html/scalenetchapt14.asp● How To: Optimize SQL Querieshttp://msdn.microsoft.com/sql/default.aspx?pull=/library/enus/dnpag/html/scalenethowto04.asp● How To: Optimize SQL Indexeshttp://msdn.microsoft.com/sql/default.aspx?pull=/library/enus/dnpag/html/scalenethowto03.asp● Microsoft SQL Server 2000 Index Defragmentation Best Practiceshttp://www.microsoft. com/technet/prodtechnol/sql/2000/maintain/ss2kidbp.mspx● Using Views with a View on Per<strong>for</strong>mancehttp://www.microsoft.com/resources/documentation/sql/2000/all/reskit/en-us/part10/c3661.mspx● Microsoft Storage <strong>Solution</strong>s — The Right Storage and Productivity <strong>Solution</strong>http://www.microsoft.com/windowsserversystem/storage/solutions/rightsolution/rightsolution.mspxStress TestingStress testing is per<strong>for</strong>med to determine the load at which the per<strong>for</strong>mance isunacceptable or the system fails. This involves loading the system beyond the use it wasdesigned <strong>for</strong> and checking <strong>for</strong> issues. Whenper<strong>for</strong>ming stress tests, new bugs or issuesoften may surface because of the high stress and load levels. At a minimum, stresstesting should load the system as defined in the business goals.If the test environment is scaled down in relation to the production environment, thelimitations of the testing environment in relation to the production environment should beconsidered in the results.

304 Stabilizing PhaseFor example, with respect to applications, there may be a failure when the number ofsimultaneous connections hit 100. This could be because of the limitation of somevariable associated with the code segment related to connection handling. Similarproblems may be encountered only during stress testing because there will bedifferences in resource consumption and low-level implementation of the same functionsbetween the UNIX and Windows plat<strong>for</strong>m.Resolving Stress IssuesStress testing should be per<strong>for</strong>med only after all issues encountered during per<strong>for</strong>mancetesting have been fixed. Bugs encountered during stress testing can be because of theapplication, the hardware configuration, or resource availability. Issues or bugs found withthe application have to be sent to the development team with any pertinent in<strong>for</strong>mation. Ifthe issues relate directly to hardware or hardware resources, they can be solved byconfiguration or adding additional resources.For example, SQL Server is not configured to take advantage of memory more than 2 GBby default. If your hardware contains additional memory, this issue can be resolved bycorrectly configuring SQL Server to take advantage of the server's available memory.Microsoft offers two utilities, Read80Trace and OSTRESS, to assist in stress testingSQL Server. To learn more or download these utilities, refer tohttp://support.microsoft.com/?kbid=887057.For detailed in<strong>for</strong>mation on scalability, refer to the following resources:● Scaling out on SQL Serverhttp://www.microsoft.com/resources/documentation/sql/2000/all/reskit/en-us/part10/c3861.mspx.● SQL Server Scalability FAQhttp://www.microsoft.com/sql/techinfo/administration/2000/scalabilityfaq.asp.● Microsoft SQL Server 2000 Scalability Project — Server Consolidationhttp://msdn.microsoft.com/library/default.asp?url=/library/enus/dnsql2k/html/sql_asphosting.asp.● Windows 2003 Per<strong>for</strong>mance and Scalabilityhttp://www.microsoft.com/windowsserver2003/evaluation/per<strong>for</strong>mance/perfscaling.mspx.Scalability TestingScalability testing is per<strong>for</strong>med to determine if the solution scales to handle an increasingworkload. The workload may be increased size, as in Very Large Databases (VLDB), ormore activity, such as transactions. Activity scalability is measured in number of userconnections, requests, reports, <strong>for</strong> example. The overall scalability is also dependent onthe hardware and the application. The application's throughput change as the load isincreased is a measure of its scalability. Also, the throughput may be measured withincreased resources along with the increased load.Scalability testing, while similar to stress testing, provides additional in<strong>for</strong>mation to assistin future solution expansion plans. Scalability testing is conducted to record how well themigrated solution will scale or increase throughput as the user workload increases. Itdiffers from stress testing because scalability testing will generally load the solution farpast the minimum load levels defined in the Planning Phase.If additional hardware is available, it is worthwhile to determine whether exceeding thelimits of the current solution requires a simple addition of hardware or a completeredesign of the system.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 305Resolving Scalability IssuesIssues of scaling should be documented as constraints of the system. If it is imperativethat the entire system scale to a certain point based on business goals, but the solutiondoes not meet these goals, then the resources (mostly hardware) have to be reevaluatedby experts. In most cases, vendors can provide support and in<strong>for</strong>mation in thisarea.Operational TestingOperational testing is required to ensure that day-to-day functionality and maintainabilityis developed and tested. This type of testing includes items such as:● Backup routines● Database maintenance tasks and schedules● Documentation and processes developed <strong>for</strong> ongoing support● Alert and monitoring processes● Disaster recovery plansIf the solution is not going to be piloted, operational testing can be expanded to ensurethat the operations team is com<strong>for</strong>table with the processes and procedures needed tomaintain the system.Resolving Operational IssuesIssues during operational testing are normally because of incomplete documentation ofthe system requirements and configuration with respect to components that are foundonly in the production environment. In most cases, the issues will have to be handled bythe operations staff who may seek in<strong>for</strong>mation and expertise from the project team.Bug Tracking and ReportingThere are several important interim milestones in the iterative process of testing andrefining the solution be<strong>for</strong>e release. The interim milestones guide the tracking and testingprocess. These milestones include:● Bug convergence● Zero bug bounce● Release candidates● Golden releaseThese milestones are discussed under the following headings.Bug ConvergenceBug convergence is the point at which the team makes visible progress against the activebug count. It is the point at which the rate of bugs that are resolved exceeds the rate ofbugs that are found.Figure 18.1 illustrates bug convergence.

306 Stabilizing PhaseFigure 18.1Bug convergence graphBecause the bug rate will still vary — even after it starts its overall decline — bugconvergence usually manifests itself as a trend instead of a fixed point in time. After bugconvergence, the number of bugs should continue to decrease until the zero bug bounce.Zero Bug BounceZero bug bounce (ZBB) is the point in the project when development resolves all thebugs raised by the Test role and there are no active bugs — <strong>for</strong> the moment. Figure 18. 2illustrates ZBB.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 307Figure 18.2Zero bug bounceAfter ZBB, the bug peaks should become noticeably smaller and should continue todecrease until the product is stable enough to release.Careful bug prioritization is vital because every bug that is fixed creates the risk ofcreating a new bug or regression issue. Achieving ZBB is a clear sign that the team is inthe final stage as it progresses toward a stable product.Note New bugs will certainly be found after this milestone is reached. But it does markthe first time that the team can honestly report that there are no active bugs — even if itis only temporary. This can help the team maintain focus on a zero-defect mindset.Release CandidatesAfter the first achievement of zero bug bounce, a series of release candidates areprepared <strong>for</strong> release to the pilot group. Each of these releases is marked as an interimmilestone. The release candidates are made available to the pilot group so they can testit. The users provide feedback to the project team, and the project team in turn continuesto improve the product and resolve bugs that appear during the pilot. As each newrelease candidate is built, there should be fewer bugs to report, prioritize, and resolve.The pilot group is discussed in m ore detail in the "Piloting the <strong>Solution</strong>" section later inthis chapterGolden ReleaseGolden release is the release of the product to production. Golden release is a milestonein the Stabilizing Phase that is identified by the combination of zero-defect and successcriteria metrics. At golden release, the team must select the release candidate that theywill release to production. The team uses the testing data that is measured against thezero-defect and success criteria metrics to make this selection.

308 Stabilizing PhaseUser Acceptance Testing and SignoffUser acceptance testing (UAT) is an additional testing process to determine if thesolution meets the customer acceptance criteria. Because this is a migration project, thedatabase and the existing solution have already passed these criteria. In most cases,only the solution's operating environment has changed.In migration projects, UAT should test whether the new solution produces the sameresults from use cases as the existing solution. Whenever possible, use acceptance testsfrom the existing solution as a base.UAT can also affect the database. Part of testing should ensure that the SQL Serverdatabase can be accessed by the client applications.User signoff is obtained when the users agree that the solution meets the needs of theend user. The user signoff is proof that the solution meets the user acceptance criteria inrelation to their business requirements. The user signoff indicates that the solutioncon<strong>for</strong>ms to the requirements of the end-user (functionality) and the enterprise(per<strong>for</strong>mance), and that the solution is ready to be deployed into production.Piloting the <strong>Solution</strong>A pilot program is a test of the solution in the production environment, and a trial of thesolution by installers, systems support staff, and end users. The primary purposes of apilot are to demonstrate that the design works in the production environment as expectedand that it meets the organization's business requirements. Pilot deployments are oftencharacterized by a reduced but key feature set of the system or a smaller end-usergroup.The pilot is the last major step be<strong>for</strong>e a full-scale deployment. Be<strong>for</strong>e the pilot, all testingmust be completed. This provides the opportunity to integrate and test other pieces of theproduction environment that do not have any equivalent in the test environment.The pilot also provides an opportunity <strong>for</strong> users to provide feedback about how thesolution works. This feedback must be used to resolve any issues or to create acontingency plan. The feedback can help the team determine the level of support thatthey are likely to need after full deployment. Some of the feedback can also contribute tothe next version of the application.Note The success of the pilot contributes heavily to the deployment schedule. Issuesdiscovered during the pilot can delay deployment until the problems are resolved.Every migration situation is unique, and some scenarios may not require a pilot program.The pilot helps minimize the risks involved with the Deployment Phase. For instance, ifthe migration involves a Perl application that is ported to run natively on the Windowsplat<strong>for</strong>m, the differences within the application could be minimal and, depending on othermitigating factors, a decision may be made not to pilot the solution.A pilot program is highly recommended in situations where any of the following instancesapply:● The deployment plan is highly complex and the deployment team requires theexperience of the pilot deployment.● The solution is prominent or critical to the organization. If the rollout must goexactly as planned, a pilot will provide additional assurance.● There is a large difference between the production and test environments.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 309●There are elements in the production environment that cannot be adequatelyverified in the test environment.Preparing <strong>for</strong> the PilotA pilot deployment needs to be rehearsed to minimize the risk of disruption <strong>for</strong> the pilotgroup. At this stage, the development team is per<strong>for</strong>ming last-minute checks andensuring that nothing has changed since pre-production testing. The following tasks needto be completed be<strong>for</strong>e starting the pilot:● The development team and the pilot participants must clearly agree on the successcriteria <strong>for</strong> the pilot. In a migration project, the main success criterion is that thenew solution effectively replaces the existing solution.● A support structure and issue resolution process must be in place. This processmay require that the support staff be trained. The procedures used <strong>for</strong> resolutionduring a pilot can vary significantly from those used during the deployment andwhen in full production.● To identify any issues and confirm that the deployment process will work, it isnecessary to implement a trial run or a rehearsal of all the elements of thedeployment.● It is necessary to obtain customer approval of the pilot plan. Work on the pilot planstarts early during the Planning Phase so that the communication channels are inplace and the participants are prepared by the time the test team is ready to deploythe pilot.● Ensure that the plan effectively mirrors the deployment process. For instance, if themigration solution is scheduled to be deployed in phases, the entire processshould be replicated <strong>for</strong> the pilot.Note It is important to remember that a pilot program tests and validates thedeployment process as well as the solution.A pilot plan should include the following:● Scope and objectives● Participating users, locations, and contact in<strong>for</strong>mation● Training plan <strong>for</strong> pilot users● Support plan <strong>for</strong> the pilot● Known risks and contingency plans● Rollback plan● Schedule <strong>for</strong> deploying and conducting the pilotConducting the PilotConducting the pilot involves deploying the applications and databases that have beenchosen to be part of the pilot. The golden release of the solution is used <strong>for</strong> pilot testingagainst an audience consisting of actual users using real-world scenarios. When the pilotis conducted in a production environment, care has to be taken to ensure that the existingapplication and databases are not jeopardized. Hence, adequate support has to beprovided while conducting the pilot to monitor and fix any issues that arise.Conducting a pilot also includes testing the accuracy of supporting documentation,training and other non-code elements, such as cutover and fallback procedures. Any

310 Stabilizing Phasechanges made to these documents during the pilot have to be noted and thedocumentation updated accordingly.Note Ultimately, the pilot leads to a decision to either proceed with a full deploymentor to delay deployment so that issues can be resolved.Evaluating the PilotAt the end of the pilot, its success is evaluated to determine whether deployment shouldbegin. The project team then needs to decide whether to continue the project beyond thepilot.It is important to obtain in<strong>for</strong>mation about both the design process and the deploymentprocess. Review what worked and what did not work so that it is possible to revise andrefine the plan be<strong>for</strong>e deployment. Examples of in<strong>for</strong>mation to be gathered include:● Training required <strong>for</strong> using the solution● Rollout process● Support required <strong>for</strong> the solution● Communications● Problems encountered● Suggestions <strong>for</strong> improvementsThe feedback is used to validate that the delivered design meets the design specification,and the business requirements. After the data is evaluated, the team must make adecision. The team can select one of following strategies:● Stagger <strong>for</strong>ward. Prepare another release candidate and release it to the originalpilot group, then to additional groups. The release to more than one group mighthave been part of the original plan or might have been a contingency triggered byan unacceptable first pilot.● Roll back. Return the pilot group to their pre-pilot state.● Suspend the pilot. Put the solution on hold or cancel it.● Patch and continue. Fix the build that the pilot is running and continue.● Proceed to the Deploying Phase. Move <strong>for</strong>ward to deploy the pilot build to the fulllive production environment.Finalizing the ReleaseThe Stabilizing Phase culminates in the Release Readiness Approved Milestone. Thismilestone occurs when the team has addressed all outstanding issues and has releasedthe solution and made it available <strong>for</strong> full deployment. This milestone is the opportunity<strong>for</strong> customers and users, operations and support personnel, and key project stakeholdersto evaluate the solution and identify any remaining issues they need to address be<strong>for</strong>ebeginning the transition to deployment and, ultimately, release.After all of the stabilization tasks are complete, the team must <strong>for</strong>mally agree that theproject has reached the milestone of release readiness. As the team progresses from therelease milestone to the next phase of deploying, responsibility <strong>for</strong> on-going managementand support of the solution officially transfers from the project team to the operations andsupport teams. By agreeing, team members signify that they are satisfied with the workthat is per<strong>for</strong>med in their areas of responsibility.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 311Project teams usually mark the completion of a milestone with a <strong>for</strong>mal sign-off. Keystakeholders, typically representatives of each team role and any important customerrepresentatives who are not on the project team, signal their approval of the milestone bysigning or initialing a document stating that the milestone is complete. The sign-offdocument becomesa project deliverable and is archived <strong>for</strong> future reference.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 31319Deploying PhaseIntroduction and GoalsAfter envisioning, planning, developing, and stabilizing, the solution is ready to bedeployed. The Deploying Phase implements the tested solution in the productionenv ironment. The migration project Release Management team deploying the solutionworks with the operations team to successfully deploy and stabilize the solution. At theclose of the Deploying Phase, customer approval <strong>for</strong> the migration is obtained, and thesolution is transferred to the operations team. It is also possible that the operations teamhandles the deployment with the aid of the project team. Irrespective of which team doesthe deployment, the key goal of the Deploying Phase is to successfully migrate the newsolu tion into the production environment as smoothly as possible, and with the leastamount of disruption to the business environment or the end users.The deployment rollout should be conducted as a series of activities. Though you canabbreviate or combine some of these activities, you cannot skip any of them completelywith out increasing risk to the project's success.Nearly all of these activities are per<strong>for</strong>med in conjunction between the project team andthe operations team. Coordination between the two teams is now a critical successfact or. All decisions should be agreed upon by both of the teams to minimize risk. Bothteam s are involved with completing the tasks and producing the deliverables shown inTable 19.1.Table 19.1: Major Tasks and Deliverables <strong>for</strong> the Deploying PhaseTasks Deliverables Responsible RolesDeploy the solution Deployment Checklist Release ManagementStabilize the deployment Deployment Checklist Release ManagementObtain the solution signoff Customer Sign Off Product ManagementTransfer ownership Project Documents Program ManagementDeploying the <strong>Solution</strong>At the close of the Stabilizing Phase, the database and applications (server side andclient side) are fully tested and are ready <strong>for</strong> deployment. The release versions of thesource code, executables, scripts, and other installation in<strong>for</strong>mation are complete anddelivered to the deployment team.

314 Deploying PhaseWhile deployment is often discussed and planned singularly, there are actually threeseparate components and technologies that must be deployed into the productionenvironment. These solution components are:● Database server● Server side application(s)● Client side application(s)Each of these components is discussed in this section. Each of these topics is dividedinto two subtopics: process and technology. The process subtopics provide an overviewof the intricacies involved with the deployment of each of the solution components. Thetechnology subtopics include in<strong>for</strong>mation on software tools that can assist with thedeployments of the solution components.Deploying the Database ServerThe database should be deployed first because the server side and client sideapplications are dependent on it. The process and technology required <strong>for</strong> setting updatabase server and implementing databases are discussed under the followingheadings.ProcessDuring the Planning Phase of the migration, all hardware needs are evaluated and anyrequired new equipment is acquired. During the Deploying Phase, the server must be setup and configured <strong>for</strong> the Windows Server 2003 environment. The following proceduredescribes the steps <strong>for</strong> deploying the database and its server:1. The server should be built and delivered by your hardware vendor based onspecifications defined during the Planning Phase. If the server will be built fromexisting equipment, ensure that the server is available and has the requiredcapacity to host the solution.2. Install any necessary hardware. Commonly, items such as additional memory,interface cards, additional storage, tape drives, or FDDA gigabit switches will needto be installed to meet operational specifications.3. Install the operating system, including any necessary service packs and patches.This step can be per<strong>for</strong>med manually or by using imaging software. This topic isdiscussed in greater detail in the technology portion of this section.4. Configure any additional hardware that was installed. For instance, if NIC cards areinstalled, they must be configured to match the settings of the network switch theywill connect to.5. Install any additional applications needed <strong>for</strong> the server, such as monitoringapplications, backup software, asset management software, and software deliveryapplications.6. Select the deployment mechanism <strong>for</strong> the database. Some possible optionsinclude:● Use automated processes, such as installation and configuration scripts,where possible.● Use manual processes <strong>for</strong> some installation and configuration. These musthave detailed, step-by-step instructions.7. Create the database deployment package by putting together the following:● Microsoft® SQL Server installation and configuration scripts.● Databaseadministration tools and utilities.a

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 315●●●●●●Database administration scripts and a scripting language such as Perl.User database migration scripts.Database administration tasks and packages, such as a maintenance plan,jobs, and backup and restore procedures.Windows® domain user accounts configuration scripts.Scripts <strong>for</strong> configuring ODBC data sources, ADO, and OLE DB connectionstrings.Scripts <strong>for</strong> configuring COM+ components <strong>for</strong> database connection.8. Create rollback scripts to undo or remove changes introduced by the deployment.If a parallel cutover strategy is being employed, the scripts should disable thereplication. Not every aspect of the fallback can be scripted. A checklist of taskswith detailed instructions should be prepared.9. Add the deployment package to the configuration management database (CMDB).Maintain change control of the release. Where a CMDB does not exist, a simplifiedone should be created <strong>for</strong> release-tracking. The purpose of updating the CMDB isto ensure that accurate knowledge is stored regarding all of the components orconfiguration items that make up the releases.10. Execute deployment package <strong>for</strong> the databases being migrated as per the phase-12. If a straight cutover strategy is used, shut down the <strong>Oracle</strong> databases. If a parallelout strategy.11. Execute the scripts to create the database and its objects. The serial cutoverstrategy will dictate the order in which the databases are migrated.cutover is used, the databases may not be shut down. However, a quiet period isrequired to enable the replication and ensure that the replication mechanism isworking properly. Start migrating the data.13. Monitor the data migration <strong>for</strong> errors. If the migration has to be aborted, therollback scripts and other fallback steps should be per<strong>for</strong>med <strong>for</strong> each of thedatabases affected by the failure (if the databases are related and have to bemigrated together).Note If you must deviate from these scripts in the production environment, makesure to alter the scripts to reflect the change and enter a note in the script ordocumentation regarding what was altered, why, and whether you noticed anyissues afterward.TechnologySetting up and configuring servers can be time-consuming, especially if additionalapplications are needed <strong>for</strong> operations, monitoring, reporting, or other purposes. Basedon the needs of the deployment, there are two ways to deploy the server: manualdeployment and automated deployment using imaging tools. Imaging tools allow <strong>for</strong>applications, operating systems, configurations, or drivers to be installed in one package,instead of as individual installations. However, imaging can only be useful when settingup identical servers usingidentical hardware, as in a clustered set.Manual DeploymentIf a manual deployment is a consideration, a few guidelines should be noted. Often,hardware vendors will provide customized installation CDs that contain specific driversand software needed <strong>for</strong> the configuration. Using these installation discs can reduce thetime needed <strong>for</strong> installation.

316 Deploying PhaseFor the detailed manual installation procedure and configuration ofWindows® 2000 Professional, Windows® XP, Windows Server 2000 AdvancedServer, and Windows 2003 Server Enterprise Edition, refer to the help documentationprovided with the Windows operating system CD.Note Manual installations of the operating system can be partially automated using ananswer file. This file provides the input that the setup needs to per<strong>for</strong>m the installationand reduces the amount of user interaction needed during the installation process. Fordetails about creating an answer file and the options available in an answer file, refer tohttp://www.microsoft.com/resources/documentation/windows/2000/server/reskit/enus/deploy/dghn_ans_wten.asp.Another tool that can be utilized to assist in manual deployments is Microsoft RemoteInstallation Services (RIS). RIS enables you to per<strong>for</strong>m system installations across anetwork using an Active Directory service. For more in<strong>for</strong>mation on RIS, refer tohttp://www.microsoft.com/windows2000/techinfo/planning/management/remote steps.asp.The RDBMS should be installed manually using the Microsoft SQL Server SoftwareDistribution CD or a network installation tool such as RIS. For more in<strong>for</strong>mation on theinstallation process <strong>for</strong> SQL Server 2000, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/instsql/in_overview_0v3l.asp.Creation of the databases and database objects can be per<strong>for</strong>med using Data DefinitionLanguage (DDL) scripts that have been generated from the test environment. Thisin<strong>for</strong>mation can also be recreated manually using the Enterprise Manager GUI, but inmost instances the large number of objects that need to be created would make thisef<strong>for</strong>t too time-consuming.To create a database using the CREATE DATABASE command, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/tsqlref/ts_create_1up1.asp.To create a database using the Create Database Wizard in Enterprise Manager, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/howtosql/ht_7_design_4g8p.asp.DDL scripts can be run using Query Analyzer, a utility installed as part of SQL Server.Third-party SQL Server tools can also be used. For more in<strong>for</strong>mation on Query Analyzer,refe r to Appendix B.Automated DeploymentImagin g is an alternate method of deploying the operating system and all applicationsand configurations simultaneously. Imaging captures a snapshot of the entire system,including the operating system, applications, desktop settings, and user preferences.Imagin g tools should be a serious consideration <strong>for</strong> deployments that consist of multipleserv ers that require the same configuration. Creating images can greatly reduce the timeneeded to prepare servers <strong>for</strong> deployment and also ensure consistent configuration.To create an image, a master system must be manually configured with all necessarysoftware. After the server has been properly configured, the image is created usingimaging software. Finally, the image can be deployed to as many servers as required.Each will be a clone of the master system.The major benefits of using the imaging tools include:● Deployments can be per<strong>for</strong>med simultaneously. All systems can be running in ashort time.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 317●All applications are bundled into the image.The major drawback of imaging is that each type of hardware configuration requires aseparate image. You can only install images on target computers that have a compatiblehardware abstraction layer (HAL) to the reference computer. For instance, if a servercontains a different graphics card, it would require a separate image.There are many different tools and utilities available that provide the capability to recordand deploy images. Here is a listing of some of these tools:● Symantec Ghost (also called Norton Ghost) captures a complete system image <strong>for</strong>redistribution. For detailed in<strong>for</strong>mation on using Symantec Ghost, refer tohttp://service1.symantec.com/SUPPORT/ghost.nsf/pfdocs/.● Automated Deployment Services (ADS) is designed to deploy Microsoft Windows2000 Server, Advanced Server and Datacenter Server, andWindows Server 2003 (all 32-bit editions). Other operating systems are notcurrently supported. For detailed in<strong>for</strong>mation on how to use ADS, refer tohttp://www.microsoft.com/windowsserver2003/technologies/management/ads/default.mspx.Deploying the Server Side ApplicationsThe steps <strong>for</strong> building the servers described in the previous section can also be used toprepare the servers <strong>for</strong> the server-side applications. Detailed guidance <strong>for</strong> setting up theserver-side applications is discussed under the following headings.ProcessThough the server will be set up to meet the needs of your specific applications,additional steps may be needed to prepare the hardware <strong>for</strong> deployment. To deploy server-side applications, follow these steps:1. Install the operating system and third-party components on the server as requiredby the application.2. Configure the server-side application components.3. Install the server-side components on the server.4. Add all configuration in<strong>for</strong>mation into the configuration management database(CMDB) and maintain change control of the release. If a CMDB does not exist, asimplified one should be created <strong>for</strong> release-tracking. Updating the CMDB ensuresthat accurate knowledge is stored regarding all of the components or configurationitems that make up the releases.5. Deploy the applications in conjunction with the deployment strategy beingemployed <strong>for</strong> the databases.6. After the database migration has been confirmed, per<strong>for</strong>m configuration changes tothe environment to activate the application.7. If a fallback is required, then the application should be shut down and the originalconfiguration that points all users back to the original application should berestored.

318 Deploying PhaseTechnologyThe server side application components can be either deployed manually or by usingimaging as discussed in the "Automated Deployment" section.Manual DeploymentIf manual deployment is chosen, each of the components of the server-side applicationshould be individually installed. First, install the language environments (such as Perl andPHP) and any third-party utilities using the vendor's software distribution. Then install theserver-side application using the golden version of the source code from the projectteam.Automated DeploymentThe deployment of the server-side applications can be automated by bundling it into theimage. The technology is the same as discussed <strong>for</strong> deploying the database.Deploying the Client ApplicationAfter the server-side applications and databases have been deployed to production andtested, the client application should be released. Often, this stage of the deployment canbe complex because of the number of users and components involved.This is usually the point in the deployment process where the end users are affected. Inmany cases, this is the first time that they are involved in the migration process. Whilethis guidance focuses on the application and database aspects of the migration, keep inmind that there are many other items to consider. For instance, documentation, training,and help desk support also need to be in place at the time of this deployment.It is quite likely that the client computers are already in use. If not, build the hardware <strong>for</strong>the client computers and deploy the required software.ProcessAs with the other stages of deployment, the client application can be deployed manuallyor through the use of automated tools. Consider the following steps when deploying theclient application.1. Create the deployment package, which can include the following:● The complete application, including the binary installation files and anyautomation files.● Client configuration and support files.● Windows domain user accounts configuration scripts.● Scripts <strong>for</strong> configuring ODBC data sources, ADO, or OLE DB connectionstrings.● Scripts <strong>for</strong> configuring COM+ components <strong>for</strong> database connection.● Acceptance test scripts and packages.2. Create rollback scripts to remove changes introduced by the deployment. Rollbackscripts provide an alternate option if an uncorrectable issue arises during theserver, database, or application deployments.3. Add the deployment package to the configuration management database (CMDB).Maintain change control of the release. Where a CMDB does not exist, a simplifiedone should becreated <strong>for</strong> release-tracking.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 3194. When the database and application migration are completed successfully, deploythe client application. In addition to the database and application deploymentstrategy, a horizontal phase-out strategy may be employed <strong>for</strong> client applications.5. If a fallback is required, then the application should be rolled back to the previousone and the original configuration that points all clients back to the originalapplication should be restored. If the fallback is due to an application issue, then ahorizontal phase-out strategy reduces the rollback ef<strong>for</strong>t.TechnologyWhen deploying the client application, additional tools may be required to efficientlymanage the deployment. Some common tools used <strong>for</strong> packaging applications andutilizing distribution channels include:● MSI (or Windows Installer) is a Microsoft solution <strong>for</strong> application packages. Thisinstaller provides additional functionality and integration with the Windowsenvironment, including elevated privileges <strong>for</strong> installation and deployment acrossan Active Directory. To download Windows Installer or learn more about it, refer tohttp://www.microsoft.com/downloads/details.aspx?FamilyID=5fbc5470-b259-4733-a914-a956122e08e8&DisplayLang=en.● Visual Studio Installer creates setups based on the Microsoft Windows Installertechnology in the Visual Studio IDE. For detailed step-by-step instructions <strong>for</strong>Visual Studio Installer, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsinstal/html/vehowvisualstudioinstallerquickstart.asp.● WinINSTALL LE creates packages by recording a snapshot of a systemsenvironment be<strong>for</strong>e and after an application is installed, then records all of thechanges between snapshots to generate the installation package. For morein<strong>for</strong>mation about WinINSTALL LE, refer tohttp://www.ondemandsoftware.com/FREELE2003 /.● Wise Package Studio is a tool used <strong>for</strong> packaging/repackaging applications usingWise script or an MSI file. Scripts, checks, and conditions can be embedded intothe package, which also helps in deploying or distributing the package. For morein<strong>for</strong>mation on Wise Package Studio, refer tohttp://www.wise.com/wps.asp?bhcp=1.● InstallShield AdminStudio can also create a scripted package file or an MSIpackage. The repackaging methodology is same as that of Wise Package Studio.For more in<strong>for</strong>mation about InstallShield, refer tohttp://www.installshield.com/downloads/isas/evalguide/AdminStudio5_Evaluator_<strong>Guide</strong>.pdf.● IntelliMirror uses a Windows Installer server to provide distributions to clientcomputers. When an application is launched, IntelliMirror checks to ensure that theapplication is loaded and up to date. If not, the needed files are downloaded andinstalled on the system. Because IntelliMirror checks <strong>for</strong> updated versioning everytime the application is launched, this software can be used to manage all futurereleases of the client application. For more details on IntelliMirror, refer tohttp://www.microsoft.com/resources/documentation/WindowsServ/2003/standard/proddocs/enus/Default.asp?url=/resources/documentation/windowsserv/2003/standard/proddocs/en-us/sag_imirror_top_node.asp.● Windows Installer automatically reads an MSI file and deploys the applicationpackaged as an MSI file. The MSI file can be customized <strong>for</strong> the features,installation location, and so <strong>for</strong>th. Windows Installer can also per<strong>for</strong>m a silent installof the MSI file when provided with that option. For an overview of Windows

320 Deploying Phase●●Installer, refer tohttp://www.microsoft.com/windows2000/en/advanced/help/default.asp?url=/windows2000/en/advanced/help/sag_WinInstall_Technology.htm?id=3991.Active Directory is a core feature in the Windows server operating system whichnot only handles security and privileges of the domain, but also has the capabilityto distribute MSI files. Group Policy policy settings can be set in Active Directory todistribute the required MSI file. Active Directory can be used efficiently to distributethe files at off hours or weekends to avoid blocking network congestion. For furtherin<strong>for</strong>mation about Active Directory, refer tohttp://www.microsoft.com/windowsserver2003/technologies/directory/activedirectory/default.mspx.Systems Management Server (SMS) is a tool from Microsoft <strong>for</strong> distributingsoftware packages. SMS has various features, such as packaging, distributing,deploying applications, and monitoring. For step-by-step procedures <strong>for</strong> distributinga package using SMS, refer tohttp://www.microsoft.com/downloads/details.aspx?FamilyID=32f2bb4c-42f8-4b8d-844f-2553fd78049f&DisplayLang=enNote The tools listed previously have not been tested in a lab environment as part ofthis solution.Change ManagementChange management is the process <strong>for</strong> controlling changes to a protected environment.In the Stabilizing Phase, changes are made to the test environment related to bug fixesand promoting the builds. Changes made to the solution in the production environmentare handled more strictly because they can affect the end users of the application as wellas other users of the production environment. Any proposed changes must go throughthe change approval process to ensure that the changes will not adversely affect theproduction environment.For detailed in<strong>for</strong>mation on Change Management, refer tohttp://www.microsoft.com/technet/itsolutions/cits/mo/smf/smfchgmg.mspx.Stabilizing the DeploymentAfter the server-side application components, database, and client-side applicationcomponents are deployed, every aspect of the deployment must be validated to ensurethat the migration has been per<strong>for</strong>med successfully. Common items to check areincluded in the deployment checklist discussed in the following sections.Deployment ChecklistThe product manager and the operations team should ensure that the solution meets thebusiness requirements and standards determined during the Envisioning Phase. Thechecklist developed during the Planning Phase should contain the acceptance criteriathat evaluate the per<strong>for</strong>mance of the solution. It should also provide a baseline <strong>for</strong> thecustomer to approve the solution. The following categories should be included in thechecklist to test the solution be<strong>for</strong>e signoff:● Server● Database● Application (client and server side)

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 321●Additional considerationsThese categories are discussed under the following headings.ServerThe following are some server-related items that should be considered <strong>for</strong> the checklist:●●●●●●●●●●●●●●●●●●●Have all relevant service packs been loaded to the production servers? Are the OSand installed service pack level well known and documented? You will need thisin<strong>for</strong>mation if the systems fail and manufacturer support is required.Have the settings from the per<strong>for</strong>mance tuning in the test environment during theStabilizing Phase been transferred correctly? At the same time, ensure that anyconfigurations unique to the testing environment have not been transferred to theproduction environment.Have backup power systems been fully tested to ensure proper operation?Are an appropriate number of replacement hard disks on hand in case of failure inan array?Are the default client connection network library settings established on the server?Are all database and application server installation settings documented (such assort orders and default language)?Has communication between servers been checked to assure that proper DNSresolution and routing is functioning as expected?Are alerts defined <strong>for</strong> key problems and conditions? Who monitors the e-mailaddress to which these are sent? Are pagers used? Has the alert system beentested?Has the team removed guest accounts from the system and checked to ensurethat this does not affect the application?Is the appropriate level of directory security set?Has security logging been implemented?Have all non-essential services and open ports on the server been identified andclosed?Has the team tested production integration with third-party systems?Have any and all event log messages been identified and investigated?Does the OS have sufficient client access licenses <strong>for</strong> the expected peak trafficloads?Are sufficient client access licenses and connections installed <strong>for</strong> the OS? Is thisbeing monitored to assure that it does not reach its limit?Are system configurations <strong>for</strong> all tiers backed up? Were scripts created to resetconfigurations in an emergency or to bring up a new server? Are they in a wellknownlocation?Have server backups been tested? Are procedures in place <strong>for</strong> proper storage andretrieval?Have clustering software configuration and failover operations been tested?

322 Deploying PhaseDatabaseThe following are some database-related items that should be considered <strong>for</strong> thechecklist:● Have all database creation scripts been executed properly and without errors?● Were the database statistics updated be<strong>for</strong>e launch?● Have the database backups been tested to ensure that backup mechanisms areoperating properly? Have restoration procedures been tested on the solutionserver and on different hardware to test failover procedures? Are off-site backupprocedures in place?● Has database security been addressed and appropriate logon accounts created?Is the system administrator's (SA) account password blank? Are applications usingthe SA account or other account(s)?● Did the team define, test, schedule, and sign-off on maintenance plans?● Has a schedule been established <strong>for</strong> the transaction log dumping that will besufficient to recover activity to the satisfaction of the business? Has it been tested?● Are sufficient client access licenses installed <strong>for</strong> the database server? Are thesebeing monitored to assure that they do not reach their limit?● Has the latest build of the database from the development environment beenmigrated, installed, tested, and verified within the production environment?● The user databases should be checked to ensure that all the data from thedatabase is transferred from the source solution to the target solution duringdeployment.● Has the database been loaded in the production environment with clean data, andhave initial inventory levels been set? Have feeds from other systems been verifiedunder load to ensure that system availability is unaffected at the time they run?● Is the database running on the default port of 1433? If so, can this be changed toanother port or ports to enhance security of the application without affecting properoperation?● Are non-essential SQL Server services running (MS Search, OLAP)? Stop them ifthey are not required.● Are non-essential databases installed on the server? Remove databases such aspubs or Northwind, but be careful not to remove needed system databases suchas model, tempdb, or master.● Is the database correctly tuned, and does it have the proper memory usagesettings applied?● Is disk space sufficient <strong>for</strong> the expected size of the data 6-12 months ahead?● Have clustering software configuration and failover operations been tested with thedatabases?Application (Client Side or Server Side)The following list offers some client-side or server-side application-related items thatshould be considered <strong>for</strong> the checklist:● Are the proper security settings <strong>for</strong> the applications set and documented?● Has application logging been enabled or disabled, as required?● Has the golden release of the applications and other components been given arelease number, archived, then deployed? Confirm that the golden release of thesource code matches the version of the application that was released.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 323●●●●●●●Are all required environmental settings <strong>for</strong> the applications set and documented?Are all third-party software or components that are required by the system installedand documented (such as version numbers and vendor contact in<strong>for</strong>mation)?Ensure that the client application properly connects to the database. Per<strong>for</strong>mcursory testing of the application that is not intrusive and does not change theproduction database. For example, running production reports is a good way totest database functionality without changing the live data.Has connectivity between the middle-tier system and any back-end systems beentested under load? Has connection pooling been monitored to assure properoperation?Are the activation types <strong>for</strong> any COM+ applications set properly? Has theapplication been tested with the consoles logged on and logged off to assure theproper identity is used?Has the application integration been tested with third-party systems?Have clustering software configuration and failover operations been tested with theapplications?Additional ConsiderationsHere are some additional considerations that could apply to your environment. Some ofthe tasks per<strong>for</strong>med here are related to operations. Validating these tasks duringdeployment ensures operations is prepared to manage the solution and SLAs can bemet.● Are scheduler jobs defined <strong>for</strong> common tasks? Jobs such as backups and healthreporting are normally scheduled through a scheduler such as cron in UNIX.These may have been migrated over.● Has a disaster recovery plan (DRP) been established that includes databaseprocedures?Who is the DRP team leader? Is the leader's contact in<strong>for</strong>mation wellknown, and is a contingency leader appointed?● Has the team enabled change-control procedures <strong>for</strong> the operations environment?● Has the team finalized the operational processes and guidelines?● Has the team developed, tested, and simulated disaster recovery procedures?● Was an external connection used when testing the application against theoperations system? The external connection should be similar to what a customerwill use.● Was solution training delivered?● Is the processing speed acceptable?● Have the business objectives and requirements been met?● Have operation tests been per<strong>for</strong>med? Steps should be taken to make sure thatthe operations team can properly track the servers and services with theirmonitoring tools.Quiet PeriodThe quiet period <strong>for</strong> the target environment begins after stabilizing the deployed solutionand continues until the deployment is complete. It usually exists <strong>for</strong> a period of 15 to 30days. During this period, the operations team manages the deployed solution.No significant changes should be made to the solution. However, a member from theproject team may aid the operations team to manage and resolve problems that canaffect the working of the deployed solution. This enables the organization to estimate the

324 Deploying Phasemaintenance costs of the solution and prepare a budget. Changes made to the solutionwill be through the process of Change Management.During the quiet period, the efficiency of the solution can be ascertained by evaluating thefollowing:● <strong>Solution</strong>'s stability● <strong>Solution</strong>'s downtime● Maintenance required by the solutionTransferring Ownership to OperationsThe final transition occurs when the project team completes its tasks and transfers theinfrastructure, documentation, and operations to the Operations team. The ownership ofthe solution is also transferred to the Operations team.The Operations team has to understand the functioning of the solution and manage it.The solution's documentation should supply in<strong>for</strong>mation required to manage the solution.The Operations team will require the following documents to handle the solution aftermigration:● User manual. The user manual details the procedures <strong>for</strong> working with thesolution. It also details the procedures <strong>for</strong> installation and solution maintenance.● Hardware specifications. This document describes the hardware used in theproduction environment.● Software specifications. This document covers the different applications, such asthird-party software used by the solution itself or used to stabilize the deployment.The software specifications also detail the different configurations and settingsapplied to the solution during or after the installation and deployment of thesolution.● Support policies and procedures. This document details the updated businesspolicies and procedures that need to be followed after the migration is complete.Project Team TasksThe project team will examine the deployment to ensure that all areas of the deploymentare successfully completed and functioning as required. A final run of the tests thatcaused discrepancies can be used to check that they have been fixed. The project teamensures that:● All the procedures of the migration have been followed.● Backups are per<strong>for</strong>med as required.● All security measures (hardware and software) are in place and operate withoutissues.● All errors and bugs are fixed.● Adequate training is provided to operations to manage the solution.● Different user accounts have been created and checked <strong>for</strong> their functionality.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 325Operations Team TasksThe operations team will check the solution to ensure that it con<strong>for</strong>ms to the businessobjectives. The operations team will:●●●●●Conduct a final run through of the solution to check its per<strong>for</strong>mance and stability.Ensure that the project team has completed all the tasks needed to complete thedeployment.Check that the tools to per<strong>for</strong>m routine tasks are set up.Review the documentation.Decide the frequency <strong>for</strong> per<strong>for</strong>ming routine tasks.Conducting Project Review and ClosureAfter the deployment of the solution is complete, the team conducts a review meeting toassess the migration project. This review covers all the phases of the migration project,including the Envisioning, Planning, Developing, Stabilizing and Deploying Phases. Bytaking the time to discuss the entire migration project, important lessons can be learnedand applied to future endeavors. This will also highlight the positive actions taken tosuccessfully migrate the solution, and the less positive decisions or actions that delayedor hindered the migration. The project review can also compare the estimated outcome ofthe migration project with the actual targets achieved.The customer sign-off signifies the end of the Deploying Phase. The solution's keystakeholders review the migrated solution and documentation and confirm that the needsof the project have been met. After this sign-off has been received, the project team canbe disengaged. The exact terms of this sign off will depend on the migration requirements<strong>for</strong> the project.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 32720OperationsIntroduction and GoalsAfter the solution has been deployed, the operations staff inherits ownership of thesolution and is required to manage and maintain it. The operations team has beenprepared <strong>for</strong> this task by its involvement in the Deploying and Stabilizing Phases and byreviewing the documentation prepared by the project team. Even if the Windows®environment existed be<strong>for</strong>e the migration, this project will have a great impact onoperational tasks and responsibilities. This chapter provides additional links to guidanceon how to operate the production infrastructure containing Microsoft® SQL Server andWindows technologies.Operational FrameworkWith the penetration of technology into every aspect of modern day business, success isbased not only on the technology but also on the people and processes that control thetechnology. The migration project has only contributed the technology and not theoperational aspects of the deployed solution. Microsoft Operations Framework (MOF) is acollection of best practices, principles, and models. It provides comprehensive technicalguidance <strong>for</strong> achieving mission-critical production system reliability, availability,supportability, and manageability <strong>for</strong> solutions and services built on Microsoft productsand technologies.The following links provide in<strong>for</strong>mation about the operational framework:● Microsoft <strong>Solution</strong>s <strong>for</strong> Infrastructure and Management (MSIM) provides in-depthtechnical procedural guidance on the management and operation of Windowsbasedservers and computer data centers. More in<strong>for</strong>mation is available athttp://www.microsoft.com/tech net/itsolutions/cits/mo/default.mspx.● A brief overview of the MOF process model and concepts is provided in "AppendixA" of the UNIX Migration Project <strong>Guide</strong> (UMPG):http://go.microsoft.com/fwlink/?LinkId=19832.● An entire discussion of MOF, its Service Management Functions (SMFs), and allthe resources that support the framework, is available athttp://www.microsoft.com/technet/itsolutions/techguide/mof/m ofpm.mspx.

328 OperationsWindows Environment OperationsThis section provides in<strong>for</strong>mation about various aspects of a Windows Server 2003deployment in an enterprise environment.System Administration●●For common administrative tasks, refer tohttp://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/windowsserver2003/proddocs/entserver/ctasks_topnode.asp.For tools, refer tohttp://www.microsoft.com/windows server2003/downloads/tools/default.mspx.● The Active Directory Operations <strong>Guide</strong> is available athttp://www.microsoft.com/downloads/details.aspx?familyid=84dfe61e-fb7b-4673-89b8-55bcc801b431&displaylang=en.●●A technical overview of network load balancing is available athttp://www.microsoft.com/technet/prodtechnol/acs/reskit/acrkappb.mspx.Security Administration●●●●●●The Windows Server 2003 <strong>Guide</strong> is available athttp://www.microsoft.com/technet/security/prodtech/win2003/w2003hg/sgch00.mspx.A source containing a wide range of security topics and technologies is available athttp://www.microsoft.com/security/guidance/default.mspx.For best practices <strong>for</strong> implementing a Microsoft Windows Server 2003 Public KeyInfrastructure, refer tohttp://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/security/ws3pkibp.mspx.In<strong>for</strong>mation on account passwords and policies is available athttp://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/security/bpactlck.mspx.In<strong>for</strong>mation on certificate templates is available athttp://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/security/ws03crtm.mspx.The Security Services FAQ is available athttp://www.microsoft.com/resources/documentation/WindowsServ/2003/standard/proddocs/enus/Default.asp?url=/resources/documentation/windowsserv/2003/standard/proddocs/en-us/safer_howto.asp.Security checklists <strong>for</strong> securing Windows 2003 Server are available athttp://www.microsoft.com/security/guidance/checklists/default.mspx.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 329Monitoring●●●In<strong>for</strong>mation on the tools available <strong>for</strong> monitoring is available athttp://www.microsoft.com/resources/documentation/WindowsServ/2003/enterprise/proddocs/enus/Default.asp?url=/resources/documentation/WindowsServ/2003/enterprise/proddocs/en-us/tools_monitoring_status.asp.For monitoring of server per<strong>for</strong>mance, refer tohttp://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/windowsserver2003/proddocs/entserver/ctasks019.asp.For monitoring of security-related events, refer tohttp://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/windowsserver2003/proddocs/entserver/ctasks018.asp.Additional Links●●●In<strong>for</strong>mation on Windows Server 2003 per<strong>for</strong>mance and scalability is available athttp://www.microsoft.com/windowsserver2003/evaluation/per<strong>for</strong>mance/perfscaling.mspx.In<strong>for</strong>mation on account management <strong>for</strong> Windows Server 2003 is available athttp://www.microsoft.com/business/reducecosts/efficiency/manageability/account.mspx.Best practices <strong>for</strong> managing Windows Server 2003 are available athttp://www.microsoft.com/technet/community/events/windows2003srv/tnt1-106.mspx.SQL Server Environment OperationsThis section provides in<strong>for</strong>mation on various aspects of a SQL Server 2000 deploymentthat can be used to ensure optimal per<strong>for</strong>mance in an enterprise environment.Per<strong>for</strong>mance is also critical to scalability.Administration● For detailed in<strong>for</strong>mation on SQL Server administration, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/adminsql/ad_adminovw_7f3m.asp.● In<strong>for</strong>mation about administration subjects is available athttp://www.microsoft.com/sql/techinfo/administration/2000/default.asp.● For detailed discussions on topics such as indexes, statistics, automation, andmemory management, refer to SQL Server 2000 Operations <strong>Guide</strong>: SystemAdministration athttp://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/sqlops4.mspx.● In<strong>for</strong>mation about backup and recovery is available athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/adminsql/ad_bkprst_9zcj.asp.● A discussion on recovery models is available athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/dnsqlmag2k/html/dbRecovery.asp.

330 OperationsSecurityFor detailed discussion on managing security, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/adminsql/ad_security_05bt.asp.MonitoringFor monitoring of system per<strong>for</strong>mance and activity, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/adminsql/ad_mon_perf_00mr.asp.Additional LinksThe following links provide in<strong>for</strong>mation on SQL Server 2000 environment operations:●●In<strong>for</strong>mation about security patch management <strong>for</strong> SQL Server is available athttp://www.microsoft.com/business/reducecosts/efficiency/manageability/patch.mspx.The SQL Server 2000 Operations <strong>Guide</strong> is available athttp://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/sqlops0.mspx.Also refer to Appendix B, "Getting the Best out of SQL Server 2000 and Windows," <strong>for</strong>links to additional in<strong>for</strong>mation about per<strong>for</strong>mance,scalability, and high availability.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 331APPENDICESAppendix A: SQL Server <strong>for</strong> <strong>Oracle</strong> ProfessionalsOne of the assumptions of this guide has been that both <strong>Oracle</strong> andMicrosoft® SQL Server database administration experience is available in the projectteam. The success of the migration depends on how well the requirements of the currentenvironment are translated into the SQL Server environment. The knowledge andinvolvement of the custodians of the current environment, the <strong>Oracle</strong> DBAs, is veryimportant. A separate set of <strong>Oracle</strong> and SQL Server DBAs working on the migration hasthe disadvantage of possible communication problems and cost. Hence training the<strong>Oracle</strong> DBAs in SQL Server will serve the purpose of per<strong>for</strong>ming the migration, retainingDBAs with valuable knowledge of the business and the databases, and preparing them tomanage the new SQL Server environment.The purpose of this appendix is to provide a primer <strong>for</strong> <strong>Oracle</strong> DBAs in the workings ofSQL Server and its administration. The transition from <strong>Oracle</strong> to SQL Server is eased bytheseveral similarities that exist between the two RDBMSs. Some of the keycommonalities include:● Relational engine. Both <strong>Oracle</strong> and SQL Server use an optimizer to generate anoptimal execution plan from alternative solutions using statistics and access paths.The execution plan can be influenced by optimizer hints.● Process architecture. Both <strong>Oracle</strong> and SQL Server have specialized processes<strong>for</strong> user connections (shared) and dedicated database functions. SQL Server usesthreads and provides CPU affinity, features that are found in <strong>Oracle</strong> on MicrosoftWindows®.● Memory architecture. In both <strong>Oracle</strong> and SQL Server, memory is broken up intobuffers or caches with separate memory areas <strong>for</strong> SQL, procedural SQL, datadictionary, and session. Database buffers or caches are manipulated in terms ofpages/blocks. Both have similar buffer replacement policies (Least Recently Usedpolicy).● Storage architecture. In both <strong>Oracle</strong> and SQL Server, the physical database isstructured as data files, system files, transaction logs, and control files. Logicalstructures to complement the physical structures are hierarchical in nature.● Backup options. <strong>Oracle</strong> and SQL Server provide various options <strong>for</strong> backing updatabases, such as online backups, full and partial backups, and transaction logbackups.● Recovery model. Both <strong>Oracle</strong> and SQL Server use transaction logs (redo) androllback. Recovery is possible using single file backups, transaction logs, and soon.● Tools. Both <strong>Oracle</strong> and SQL Server employ Enterprise Manager, SQL clientArchitectureAn understanding of SQL Server architecture and how it compares and contrasts with<strong>Oracle</strong> is fundamental in shaping the migration as well as extracting the optimalper<strong>for</strong>mance out of the SQL Server plat<strong>for</strong>m.

332 Appendices<strong>Oracle</strong> and SQL Server are very similar in their architecture and internal workings.However, the same terms have different meanings in the two environments. For example,in <strong>Oracle</strong> the term instance is used <strong>for</strong> the memory and processes that support an <strong>Oracle</strong>database. However, in SQL Server, the term instance contains the memory, processes,and also the user databases. Irrespective of the terminologies used, SQL Server alsouses memory and process components in a manner similar to <strong>Oracle</strong>. In this discussion,SQL Server is presented to the <strong>Oracle</strong> DBA using an <strong>Oracle</strong>-like view.Database and InstanceA database, by definition, is the repository <strong>for</strong> data and metadata (data dictionary). Thisdefinition is universal in nature. In <strong>Oracle</strong>, the term database is used to specifically referto the files that are used to store the database's data and metadata. The term instance isused <strong>for</strong> the memory structures (System Global Area is the main component) andprocesses that are required to access and per<strong>for</strong>m work against the database. In SQLServer, the instance is used collectively <strong>for</strong> the data files, memory, and processes. FigureA.1 illustrates the similarities between instances of <strong>Oracle</strong> and SQL Server with respectto memory and processes. Only the important components of an instance—the SGA andthe processes — are covered in the figure. Details of the SQL Server architecture can befound at http://msdn.microsoft.com/SQL/sqlarchitecture/default.aspx.Figure A.1<strong>Oracle</strong> and SQL Server 2000 – High level comparison of Instance and Database in <strong>Oracle</strong> and SQLServer to show architectural similaritiesApart from the defined meaning of the terms instance and database in <strong>Oracle</strong> and SQLServer, the terms are used very loosely to mean an occurrence of the database. Thephrase “multiple instances or multiple databases running on a single database server” isa typical usage of this terminology. Database administrators should be able to infer themeaning from the context.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 333What can be confusing with SQL Server is the presence of several system and usercreated“databases” inside a SQL Server database. Hence the term database systemhas been coined here to mean an occurrence of <strong>Oracle</strong> or SQL Server. MultipleDatabase Systems (Instances)In <strong>Oracle</strong>, multiple database systems can be created on a single server and the creationis independent of the software installation (using the CREATE DATABASE SQLcommand). The same is not true with SQL Server. The initial database system (default ornamed) is created as part of the software installation. The software distribution is alsoneeded to create additional database systems. For in<strong>for</strong>mation on working with namedand multiple instances of SQL Server 2000, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/instsql/in_runsetup_2xmb.asp.The following components are shared between all of the instances running on the samecomputer:● There is only one SQL Server 2000 program group (Microsoft SQL Server) on thecomputer, and only one copy of the utility represented by each icon in the programgroup. There is only one copy of SQL Server Books Online.● The versions of the utilities in the program group are from the first version of SQLServer installed on the computer.● There is only one copy of the MSSearchService that manages full-text searchesagainst all of the instances of SQL Server on the computer.● There is only one copy each of the English Query and Microsoft SQL Server 2000Analysis Services servers.● The registry keys associated with the client software are not duplicated betweeninstances.● There is only one copy of the SQL Server development libraries (include and .libfiles) and sample applications.Extending out to the client tier, the <strong>Oracle</strong> clients and SQL Server clients connect todatabases in similar, albeit proprietary, protocols: Transparent Network Substrate (TNS)<strong>for</strong> <strong>Oracle</strong> and Tabular Data Stream (TDS) <strong>for</strong> SQL Server. Figure A.2 compares theuser-instance-database interaction paths.

334 AppendicesFigure A.2<strong>Oracle</strong> and SQL Server 2000 — User-instance database interaction comparedUnlike <strong>Oracle</strong>, SQL Server does not store client configuration in<strong>for</strong>mation in an operatingsystem file. SQL Server uses registry keys to store such in<strong>for</strong>mation. By default, SQLServer is configured to listen on TCP/IP network protocol, which should suffice <strong>for</strong> mostinstallations migrating from <strong>Oracle</strong>. The server network utility (part of the serverinstallation) can be used to configure SQL Server to listen on named pipes, multiprotocol,NWLink, IPX/SPX, Banyan VINES, and Appletalk protocols.On the client side, the client network utility (part of the client installation) can be used toset up alias names <strong>for</strong> SQL Servers. The alias names can be mapped to an IP address ora named pipe address. The naming varies based on the type of installation. Clients canconnect to:● A default instance by specifying the servername.● A named instance by specifying the servername\instancename.The proper instance naming will have to be used while defining Data Source Names(DSN) in the connection string of ODBC, ADO, DBI::DBD, Enterprise Manager, QueryAnalyzer, and isql utility.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 335Database ArchitectureA database has one or more physical data files that contain all the database data. Thisfact has not changed from the early days of data repositories, such as Sequential AccessMethods (SAM), Indexed Sequential Access Method (ISAM), and Virtual Storage AccessMethod (VSAM), to the modern day relational database management systems (RDBMS).Though hardware throughput has improved in the past several years, the improvement indata access rates is not purely hardware-related, but also in part to the evolution of thedatabase storage architectures.Physical Storage ArchitectureThe physical architecture is made up of files that contain the system (or catalog) andapplication data. As with <strong>Oracle</strong>, SQL Server also has support <strong>for</strong> raw devices. Thephysical architecture is used to provide separation of data based on its type, such asmetadata from user data; heap data from index data; user data from DBMS data(including transaction logs), and permanent data from temporary data.The <strong>Oracle</strong> physical architecture is made up of data files, redo log files, and control files.SQL Server database systems have four system databases (master, model, tempdb,and msdb) and one or more user databases. Each of these databases has one or morefiles. Each database has its own transaction log files, which are separate from the datafiles.Logical Storage ArchitectureFor the convenience of administration and efficiency of use, the physical storage isbroken down into smaller logical structures. By dividing each physical data file intoseveral logical structures, and allocating space to each database object in increments ofthese smaller logical structures, access to the database objects can be insulated from thephysical file storage on the operating system. SQL Server has a storage hierarchy whichis similar to <strong>Oracle</strong>’s block-extent-segment-tablespace implementation.This enables you to load smaller chunks of data into memory <strong>for</strong> faster data access andalso enables you to move the physical location of a data file in the file system,transparent to the database objects or the applications that access them. Figure A.3shows the hierarchy of storage structures available in <strong>Oracle</strong> and SQL Server.Figure A.3Physical and Logical storage structure hierarchies in <strong>Oracle</strong> and SQL Server

336 AppendicesIn SQL Server, the term page is used instead of blocks. The data files are <strong>for</strong>matted intoblocks (pages) of the same size (8 KB). The unit of transfer <strong>for</strong> data between storage anddatabase memory is a block or page. The composition of the SQL Server page is similarto the <strong>Oracle</strong> block and is made up of page header, data rows and row offset array (rowdirectory). Free and used space is also tracked and managed similarly. SQL Server doesnot allow rows larger than 8060 bytes. This restriction, however, does not apply to rowscontaining large data types such as text, image, and so on, which can be storedseparately.Although the data is stored in blocks, the block is too small a unit <strong>for</strong> allocation to thedatabase objects. A bigger unit called extent, which corresponds to a specific number ofcontiguous data blocks, is used <strong>for</strong> this purpose. SQL Server only supports fixed sizeextents of 64 KB (8 pages).For more details on the two types of extents and how they are used, refer to the “Pagesand Extents” article at http://msdn.microsoft.com/librar y/default.asp?url= /library/en-us/architec/8_ar_da2_4iu r.asp.Also refer to the “Managing Extent Alloc ations and Free Space” article athttp://msdn.mic rosoft.com/library/d efault.asp? url=/library/en-us/architec/8_ar_da2_4lgl. asp.The SQL Server equivalen t of the <strong>Oracle</strong> tables pace is called the filegroup. Each SQLServer database is created with a primary file belonging to the default primary filegroup.Optionally, secondary datafiles can be added to the primary filegroup or additionalfilegroups can be created. Files and filegroups in SQL Server are implemented along thesame lines as datafiles and table spaces in <strong>Oracle</strong>.Instance ArchitectureThis section covers the two components that make up an <strong>Oracle</strong> instance: memory andprocesses and its SQL Server equivalents.Memory ArchitectureThe design of database m emory architecture in both <strong>Oracle</strong> and SQL Ser ver are basedon the same objective. This objective is to acquire memory from the syste m and make itavailable to the RDBMS to per<strong>for</strong>m its work. Because the available memory is a verysmall percentage of the database size, the configuration of memory is very important tothe per<strong>for</strong>mance of the database system. The memory per<strong>for</strong>mance has to be optimizednot only <strong>for</strong> application data, but also the data dictionary and the needs of the relationalengine. For SQL this includes procedures, execution plan, cursors, temporary objects,and sorting.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 337The SQL Server memory address space is illustrated in Figure A.4:Figure A.4SQL Server Address SpaceA 32-bit process is normally limited to addressing 2 GB of memory, or 3 GB if the systemwas booted using the /3G boot switch in boot.ini, even if there is more physical memoryavailable. However, both <strong>Oracle</strong> and SQL Server can use the MS Windows 2000Address Windowing Extensions (AWE) API to support up to a maximum of 64 GB ofphysical memory. The specific amount of memory is dependent on the hardware andoperating system versions. The AWE-enabled server configuration parameter is availablein SQL Server <strong>for</strong> the purpose. The Microsoft Knowledge Base Article 274750, "How toconfigure memory <strong>for</strong> more than 2 GB in SQL Server," is available athttp://support.microsoft.com/default.aspx?scid=kb;en-us;274750. It provides in<strong>for</strong>mationon the maximum amount of memory that various Microsoft Windows Operating Systemversions can support and how to configure memory options.An overview of the internals of memory management facilities of SQL Server 2000 isavailable at http://msdn.microsoft.com/sql/default.aspx?pull=/library/enus/dnsqldev/html/sqldev_01262004.asp.The SQL Server 2000 memory manager uses different algorithms to manage memory ondifferent versions of Windows. While memory allocation to the RDBMS has been rigidlycontrolled in <strong>Oracle</strong> by the configuration (initialization) parameters, the sizes of thecomponents in SQL Server 2000 address space are auto-tuned dynamically incooperation between the RDBMS and the operating system. All memory areas within thememory pool are also dynamically adjusted by the SQL Server code to optimizeper<strong>for</strong>mance and do not need any administrator input.The Memory Pool is the SQL Server equivalent of the SGA. The composition of thememory pool can be found athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/architec/8_ar_sa_1zu4.asp.

338 AppendicesProcess/Thread ArchitectureThe process architecture identifies the various database related processes and theirfunctionality. As is true with <strong>Oracle</strong> on Windows, SQL Server also uses a thread-basedarchitecture. SQL Server does not differ significantly from <strong>Oracle</strong> in its use of pools ofprocesses (threads) <strong>for</strong> system functions and user requests. Table A.1 compares SQLServer functionality with respect to <strong>Oracle</strong> background processes.Table A.1: Mapping of <strong>Oracle</strong> and SQL Server Background Processes<strong>Oracle</strong> Process(Required Status)*<strong>Oracle</strong>IdentifierMin / MaxSQL Server Process(Required Status)*Min / MaxProcess Monitor (M) PMON 1 / 1 Open Data Services (M) 1 / 1System Monitor (M) SMON 1 / 1 Database cleanup / 1 / 1shrinking (M)Database Writers (M) DBWn 1 / 20 Lazywriter (M) 1 / 1Checkpoint Process (M) CKPT 1 / 1 Database checkpoint (M) 1 / 1Recoverer (O) RECO 0 / 1 MS DTC (O) 0 / 1Log Writer (M) LGWR 1 / 1 Logwriter (M) 1 / 1Archive Processes (O) ARCn 0 / 10 N/AJob Queue Processes Jnnn 0 / 1000 SQL Agent (O) 0 / 1(O)Job Queue Coordinators CJQn 0 / 1 SQL Agent (O)0 / 1(O)Queue MonitorQMNn 0 / 10 SQL Agent (O) 0 / 1Processes (O)Parallel Query Slave Pnnn 0 / 3600 Worker threads (M) 32 / 32767Processes (O)Dispatcher (O) Dnnn 0 / 5 Network thread (M) 1 / 1Shared Servers (O) Snnn 0 / OS Worker threads (M) 32 / 32767SQL Server employs sophisticated shared server architecture. On startup, SQL Servercreates a User Mode Scheduler (UMS) o bject <strong>for</strong> each processor using the affinity masksetting. A pool of worker threads is created by Open Data Services (ODS) to handle usercommands, and their control is distributed among the UMS schedulers. This architecturemimics the shared server-dispatcher concept in <strong>Oracle</strong>. While in <strong>Oracle</strong> the shared serverprocesses are schedule d by the operating system, SQL Server uses the UMS toschedule worker threads.The internal workings of the User Mode Scheduler are available at:http://msdn.microsoft.com/SQL/sqlarchitectu re /default.aspx?pull=/library/en-us/dnsqldev/html/sqldev_02252004.asp?frame=true.Additional references on topics related to process architecture include:● Server Memory Options (Administrating SQL Server):http://msdn.microsoft.com/library/default.asp?url=/library/en-us/adminsql/ad_config_9zfy.asp.● SQL Server Memory Usage: http://support.microsoft.com/default.aspx?scid=kb;enus;321363.● 64-bit Overview: http://www.microsoft.com/sql/64bit/productinfo/overview.asp.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 339●IO Affinity: http://support.microsoft.com/default.aspx?scid=kb;[LN];298402.● Allocating threads to a CPU:http://msdn.microsoft.com/library/default.asp?url=/library/enus/architec/8_ar_sa_8agl.asp.Relational Engine ArchitectureThe Relational Engine is the part of the RDBMS that is responsible <strong>for</strong> parsing,optimizing, and executing the SQL statements received from end users and returningresults (also known as fetching) to the end users.Figure A.5 illustrates the components of SQL Server relational engine.Figure A.5Components of SQL Server Relational EngineFigue A.5 illustrates the main components of the relational engine portion of SQL Server.The illustrated components can be organized into three groupings of subsystems:Compilation, Execution, and SQL Manager. The components parser, T-SQL compiler,normalizer, and query optimizer belong to the compilation subsystem, which processesthe SQL statements. These statements typically come in as TDS messages. The SQLManager, in the middle of the figure, <strong>for</strong>ms the second subsystem, which controls theflow of everything inside the SQL Server. Remote Procedure Call (RPC) messages arehandled directly by the SQL Manager. T-SQL execution, query execution, and expressionservice <strong>for</strong>m the execution subsystem. The query results come out of the expressionservice and are sent back out by ODS, after <strong>for</strong>matting the results into TDS messages.The expression services library per<strong>for</strong>ms data conversion, predicate evaluation orfiltering, and arithmetic calculations.The catalog services component handles data definition statements (DDL). The UMS is ascheduler internal to SQL Server that handles the threads and fibers. The system-storedprocedures are self evident.For a more detailed discussion of the relational engine, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/dnsql7/html/sqlquerproc.asp.The concepts of execution plan, cost based optimization, and hints are common to<strong>Oracle</strong> and SQL Server.A white paper on query optimizer and statistics is available athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/dnsql2k/html/statquery.asp.

340 AppendicesTransaction ArchitectureUsers and applications interact with the database using transactions. Both <strong>Oracle</strong> andSQL Server offer both optimistic and pessimistic concurrency control. Pessimistic lockingis the default <strong>for</strong> SQL Server. Microsoft SQL Server supports all four levels of isolation:read uncommitted, read committed, repeatable read, and serialization. Read committedis the default level of isolation <strong>for</strong> SQL Server.Like most RDBMSs, <strong>Oracle</strong> and SQL Server achieve isolation by controlling concurrentaccess to shared resources (such as schema objects) and their subcomponents (such asdata rows), and internal database structures using locks. Transactions acquire locks atdifferent levels of granularity. In <strong>Oracle</strong>, the granularities are row and table, while in SQLServer the granularities are row (RID and rowid), key (row lock within an index), page,exte nt, table, and database. A major difference between <strong>Oracle</strong> and SQL Server in theiruse of locks is that <strong>Oracle</strong> does not escalate locks, while SQL Server escalates locks toreduce the system overhead of maintaining a large number of finer-grained locks. SQLServer automatically escalates row locks and page locks into table locks when atransaction exceeds its escalation threshold.Table A.2 compares the types of locking available in <strong>Oracle</strong> and SQL Server.Table A.2: Comparison of the Modes of Locking in <strong>Oracle</strong> and SQL Server<strong>Oracle</strong> SQL Server PurposeShare (S) Shared (S) Used <strong>for</strong> operations that do not changedata, such as SELECT statementsRow Share (RS) Update (U) Used on resources that can be updated,such as SELECT … FOR UPDATE in<strong>Oracle</strong> and SELECT statements withthe UPDLOCK lock hint in SQL ServerRow Exclusive (RX) Exclusive (X) Used <strong>for</strong> data modification operations,such as INSERT, UPDATE, DELETEShare Row Exclusive N/A Only allows non-update S and RS locks(SRX)Exclusive (X) Exclusive (X) Disables all other updatesN/A Intent Shared (IS) Indicates intention to read someresources lower in the hierarchyN/A Intent Exclusive (IX) Indicates intention to modify someresources lower in the hierarchyN/A Shared with IntentExclusive (SIX)Indicates intention to read all resourcesat a lower level and modify some ofthem using IX locksExclusive DDL Schema Modification For per<strong>for</strong>ming DDL(Sch-M)Breakable Parse Schema Stability For compiling queries(Sch-S)N/ABulk Update (BU) For bulk copying data into a tableSQL Server Books Online has very useful in<strong>for</strong>mation on lock modes, lock hints, lockcompatibility, and deadlocks. More in<strong>for</strong>mation is available athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/architec/8_ar_sa2_2sit.asp.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 341Security ArchitectureThe database has security mechanisms such as logins, privileges, and roles to providecontrol over privileges to connect to the database, access schema objects, andmanipulate their structure and data. Both <strong>Oracle</strong> and SQL Server utilize a layeredapp roach to security, from logins to roles to system (statement) and object privileges.LoginsBoth <strong>Oracle</strong> and SQL Server provide logins <strong>for</strong> authorized users to connect to thedatabase. In <strong>Oracle</strong>, the login is called user or username, and in SQL Server, it is calledlogin identifier or simply login. Any operation the user can per<strong>for</strong>m is controlled by theprivileges granted to the login.AuthenticationBoth <strong>Oracle</strong> and SQL Server allow authentication by the operating system or by thedatabase (server). In SQL Server, the operating system mode is called WindowsAuthentication Mode and the database mode is called SQL Server Authentication Mode.SQL Server can operate in either Windows authentication mode or Windows and SQLServer authentication mode.PasswordsThe features and functionality related to passwords, such as complexity, aging, or lockout, that exist with <strong>Oracle</strong> logins, can only be found in Windows logins and not SQLServer authenticated logins.Privileges<strong>Oracle</strong> and SQL Server have a similar model to secure schema objects and applicationdata and system objects and metadata from unauthorized users. This is achieved bycreating two sets of privileges: system (statement) privileges (permissions) and objectprivileges (permissions). Privileges can be assigned to users and roles using the GRANTstatement and removed using the REVOKE statement. Roles are used to grant privilegesto users, but indirectly, are discussed next.Roles<strong>Oracle</strong> provides predefined roles, the most familiar being CONNECT, RESOURCE, DBA,and so on. Similarly, SQL Server has several predefined roles with specific permissions.There are two types of predefined roles: fixed server roles and fixed database roles. Both<strong>Oracle</strong> and SQL Server offer user-defined roles.For more in<strong>for</strong>mation on the privileges available in SQL Server and their management,refer to http://msdn.microsoft.com/library/default.asp?url=/library/enus/adminsql/ad_security_94dv.asp.For in<strong>for</strong>mation on creating user-defined roles in SQL Server, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/adminsql/ad_security_6x5x.asp.Microsoft SQL Server 2000 SP3 Security Features and Best Practices is available at:http://www.microsoft.com/sql/techinfo/administration/2000/security/securityWP.asp. Itprovides a detailed account of SQL Server security model and best practices.

342 AppendicesData DictionaryThe data dictionary, referred to in SQL Server as the system catalog, is broken up into asystem-level component in the master database and individual database-levelcomponents in each of the other databases. It has the following characteristics:● Each of the databases contains tables to maintain its own database objects(tables, indexes, constraints, users, privileges, replication definition) and othersystem structures (filegroups, files).● The centralized system catalog in the master database contains in<strong>for</strong>mation whichis a combination of <strong>Oracle</strong> control files and data dictionary, such as individualdatabase names and primary file location, server level logins, system messages,configuration (initialization parameter) values, remote servers, linked servers,system procedures (such as the DBMS_ <strong>Oracle</strong> stored programs), and so on.The features of the data dictionary that an <strong>Oracle</strong> DBA is familiar with — system tables,views, functions, and procedures — can also be found in SQL Server in the following<strong>for</strong>ms:● System tablesThese serve the same function as <strong>Oracle</strong>’s data dictionary tables. The systemtables should be used <strong>for</strong> in<strong>for</strong>mation only.System tables available under the master database store server-level systemin<strong>for</strong>mation. For example:● master..syslogins — Available login accounts● master..sysdatabases — Available databasesThe following tables store database-level system in<strong>for</strong>mation <strong>for</strong> the respectivedatabase:● sy susers — Available user accounts with privileg es on database● sysobjects — Available objects in database● sysindexes — Available indexes in databaseFor a complete listing of system tables and their use, refer tohttp:// msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_sys_00_690z.asp.● In<strong>for</strong>mation schema viewsSQL Server offers in<strong>for</strong>mation schema views which are equivalent to the ALL_views found in <strong>Oracle</strong>. In<strong>for</strong>mation can be retrieved from these views by queryingthe corresponding INFORMATION_SCHEMA.view_name. For example, the viewsthat are visible to a user can be verified by usingINFORMATION_SCHEMA.VIEWS. Below is a list of common in<strong>for</strong>mation schemaviews.● in<strong>for</strong>mation_schema.tables — Available tables in a database● in<strong>for</strong>mation_schema.columns — Available columns in a database● in<strong>for</strong>mation_schema.table_privileges — Available privileges on tables in adatabaseThe in<strong>for</strong>mation schema views topic is discussed athttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_iaiz_4pbn.asp.● System functions

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 343●Equivalents <strong>for</strong> built-in <strong>Oracle</strong> SQL functions can be found in SQL Server under theSystem functions heading. Some commonly used functions include:● User_name(id)● getdate()● system_user()For a list of all available SQL Server system functions, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_fafz_79f7.asp.System stored proceduresThe system stored procedures aid the administrator in per<strong>for</strong>ming commonfunctions by supplementing the DDL. They also provide in<strong>for</strong>mation from systemtables, prepackaged to save the administrator from writing his or her own queriesand views. The system stored procedures can be considered to be the equivalentof <strong>Oracle</strong>'s DBMS and UTL packages. These procedures are designed to becomprehensive and remove the burden of having to remember DDL syntax andsystem table names.For a complete listing of system stored procedures, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_sp_00_519s.aspAdministrationThis section provides brief introductions to topics such as export, import, backup,recovery, and monitoring.Export/ImportIn SQL Server, data can be imported and exported using the Data Trans<strong>for</strong>mationServices (DTS) tool, Transact-SQL statements (INSERT INTO and BULK INSERT), andBulk Copy utility (bcp), which provides the same functionality as SQL*Loader.ExportSQL Server does not have an equivalent of the <strong>Oracle</strong> export utility to move data into abinary <strong>for</strong>mat file. Individual schema objects can be backed up to text-based flat files inany of the several available file <strong>for</strong>mats, or they can be exported to any of the severalOLE DB destinations and restored using tools and utilities.One of the following methods can be used to extract or spool data into flat files:● Using the tool osql.exe is similar to SQL*Plus in the way the users can runcommands at the prompt.● Using bcp, the bulk copy utility● Using the D ata Trans<strong>for</strong>mation Services (DTS) toolImportSQL Server does have an equivalent to the <strong>Oracle</strong> import utility, but as mentioned in theprevious section, individual schema objects that have been exported to flat files with anyof the several supported file <strong>for</strong>mats or to any OLE DB destination can be imported into adatabase using one of the many tools and utilities.Three ways that data can be imported into SQL Server include:

344 Appendices●●●Using the BULK INSERT command, which acts as an interface to the bcp utility.The structure of the BULK INSERT command is similar to the structure of thecontrol file used in SQL*Loader.Using bcp, the bulk copy utility.Using the Data Trans<strong>for</strong>mation Services (DTS) tool.The functionality and use of bcp, BULK INSERT, and DTS <strong>for</strong> moving data from <strong>Oracle</strong>int o SQL Server have been demonstrated in Chapter 8. DTS has also been discussed inmore detail in Appendix B: "Getting the Best out of SQL Server 2000 and Windows."Some additional references on these utilities are:●●●the "DTS Package Development, Deployment and Per<strong>for</strong>mance" article availableat http://support.microsoft.com/default.aspx?scid=kb;en-us;242391&sd=tech.For in<strong>for</strong>mation on different switches available with BULK INSERT, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/tsqlref/ts_babz_4fec.asp.For tips on optimizing bulk copy read, refer tohttp: //www.databasejournal.com/features/mssql/article.php/3095511.BackupIn <strong>Oracle</strong>, backup methods can be categorized at a high level as physical and logicalbackups. Comparable methods <strong>for</strong> backing up the database can be found in SQL Server.Table A.3 provides a comparison of the available methods:Table A.3: Backup Methods in <strong>Oracle</strong> and SQL ServerBackup Method <strong>Oracle</strong> SQL ServerLogical Export bcp or DTSPhysical Cold ColdPhysical Online FullPhysical Incremental Transaction log orDifferentialPhysical Archive log Transaction logLogical BackupsThe goal of a logical backup is to be able to recover at the individual schema object level.Although <strong>Oracle</strong>'s export and import utilities are designed <strong>for</strong> moving <strong>Oracle</strong> data, theycan be used as a supplemental method of protecting data in an <strong>Oracle</strong> database. It is notrecommended to use logical backups as the sole method of data backup.SQL Server does not support logical backups to proprietary binary <strong>for</strong>mat files. Individualschema objects, however, can be backed up to flat files in any of the several supportedfile <strong>for</strong>mats and restored using tools such as the bcp utility and DTS tools.Physical BackupsIn <strong>Oracle</strong>, a physical backup involves making copies of database files including datafiles,control files, and, if the database is in ARCHIVELOG MODE, archived redo log files. Thesame is true in SQL Server, though a backup is viewed to be at the database level.Larger databases can utilize filegroup backups to back up sections of a database. Thephysical backups available are:● Cold (offline) backups. A cold backup or a closed backup can be described as abackup of one or more database files taken while the databaseis closed and is not

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 345available <strong>for</strong> user access. Even though the term cold backup is not mentioned inthe documentation, the method can be applied <strong>for</strong> per<strong>for</strong>ming backups in SQLServer.● Online backups. A backup is termed as an online backup or a hot backup if it istaken while the database is open and is accessible to users. SQL Server fullbackup backs up a complete database and includes transaction log entries. Fileand filegroup backups can be made using the BACKUP DATABASE statement orthrough Enterprise Manager ->Backup Database -> File and filegroup.Transaction logs can be backed up separately as well.Incremental BackupsPhysical incremental backups are per<strong>for</strong>med to capture only the changed blocks, therebyreducing the time and space needed <strong>for</strong> the backups. Incremental backups areper<strong>for</strong>med after an initial complete backup has been per<strong>for</strong>med. In SQL Server,differential backups contain only data that has changed since a last full backup.Differential database backups can be made using the BACKUP DATABASE statement orthrough Enterprise Manager -> Backup Database -> Database — differential.RecoveryThe three recovery models offered by SQL Server—Full, Bulk-logged, and Simple—arediscussed below.● Full recovery model. This is used when the data is critical and must berecoverable to point of failure. All recovery options are available in this recoverymodel. This is equivalent to <strong>Oracle</strong>’s ARCHIVELOG mode (when theNOLOGGING option is not specified at any level), where all transactions arelogged and logs are archived <strong>for</strong> full recoverability.● Bulk-logged recovery model. This is the mid-level recovery model available <strong>for</strong>bulk operations such as bulk copy, SELECT INTO, and text processing. Thisrecovery model does not provide point-in-time recovery past the beginning of anybulk operation. This is similar to setting the NOLOGGING option at the tablespace,object level, or <strong>for</strong> individual commands to avoid logging of bulk operations.● Simple recovery model. This is used when it is not important to completelyrecover the database or the lost data can be recreated. This recovery model hasthe lowest logging overhead. This is equivalent to running the database inNOARCHIVELOG mode.For more in<strong>for</strong>mation on the backup and recovery architecture of SQL Server, refer tohttp://msdn.microsoft.com/library/en-us/architec/8_ar_aa_9iw5.asp.A detailed account of the backup and recovery options and techniques, as well asguidance <strong>for</strong> per<strong>for</strong>ming these administrative tasks, is available athttp://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/sqlops4.mspx.MonitoringMonitoring should be per<strong>for</strong>med <strong>for</strong> availability, errors, and per<strong>for</strong>mance.

346 AppendicesAvailabilityAvailability should cover the server(s), node(s), database services, and database.●●●Server. Monitoring of the server should also include the network access path fromthe application or client to the server. The most common method to achieve this isa ping test.Database Services. A common mode of monitoring <strong>Oracle</strong> databases is to checkon the instance-specific processes such as SMON or PMON. Because SQL Serveruses thread architecture, only the main process (sqlservr.exe) can be monitored.Database. Even when the services are running, connecting to a database may faildue to some errors. A second level monitoring involving connecting to thedatabase and per<strong>for</strong>ming some simple tasks should expose such errors.The command line utility scm (Service Control Manager) can be used to check the healthof a SQL Server instance. Scripts can also be executed using SQL Server command lineutilities such as isql or osql.ErrorsIn a database environment, errors, failures, or faults can occur in a number of areas.Erro rs have to be monitored by viewing (or mining) the error logs. The server event logsand the database instance logs are a good source <strong>for</strong> errors and violations.The event log, which contains entries <strong>for</strong> all database server instances and otherapp lications running on the server, can be accessed through the Microsoft WindowsEve nt Viewer utility. This can be accessed through Start -> Program -> AdministrativeTools -> Event Viewer. The events in the event log can be filtered by type, source, daterange, and so on.SQLServer has predefined error codes and error messages (see master..sysmessages<strong>for</strong> a complete list) that give in<strong>for</strong>mation such as unique error number, severity level, errorstate number, and error message on all errors.The SQL Server error logs provide complete in<strong>for</strong>mation regarding all events, auditingmessages, errors, and so on, that have occurred against an instance. The error logs canbe viewed using a text editor or through Enterprise Manager. In Enterprise Manager, thelogs can be found using SQL Server Group -> Server Instance -> Management ->SQL Server Logs.Per<strong>for</strong>mancePer<strong>for</strong>mance Monitor and Task Manager are two of the several tools that can be used tomonitor resource usage at the server level as well as the SQL Server instance level. Thefollowing is a listing of the methods by which various server and database resources canbe monitored:● CPU. Task Manager: Per<strong>for</strong>mance, Per<strong>for</strong>mance Monitor: Processor● Memory. Task Manager: Per<strong>for</strong>mance, Per<strong>for</strong>mance Monitor: Memory● Process. Task Manager: Processes, Per<strong>for</strong>mance Monitor: Process● Virtual Memory. Task Manager: Per<strong>for</strong>mance, Per<strong>for</strong>mance Monitor: Paging File● Network. Task Manager: Networking, Per<strong>for</strong>mance Monitor: Network Interface● I/O. Task Manager: Processes, Per<strong>for</strong>mance Monitor: LogicalDisk and Pe<strong>for</strong>manceMonitor: PhysicalDisk● Storage.My Computer, Windows ExplorerSome references on monitoring SQL Server per<strong>for</strong>mance are:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 347●●●●●●"Job to Monitor SQL Server 2000 Per<strong>for</strong>mance Activity" is available athttp://support .microsoft.com/default.aspx?scid=kb;EN-US;283696."How to monitor SQL Server 2000 blocking" is available athttp://support.microsoft.com/default.aspx?scid=kb;en-us;271509&Product=sql2k."How to View SQL Server 2000 Activity Data" is available athttp://support.microsoft.com/default.aspx?scid=kb;en-us;283784&Product=sql2k."How to View SQL Server 2000 Blocking Data" is available athttp://support.microsoft.com/default.aspx?scid=kb;en-us;283725&Product=sql2k."How To: View SQL Server 2000 Per<strong>for</strong>mance Data" is available athttp://support.microsoft.com/default.aspx?scid=kb;en-us;283886&Product=sql2k.Tools and functions to automate administration is available athttp://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/sqlops4.mspx.

348 AppendicesThe per<strong>for</strong>mance of a SQL Server installation is dependent on several factors coveringdatabase design, application design, query design, access methods (indexing schemesand views), hardware, and software resources. The following references cover the entirebreadth of topics that are critical to getting the best per<strong>for</strong>mance out of SQL Server.● "The Data Tier: An Approach to Database Optimization" is available athttp://www.microsoft.com/resources/documentation/sql/2000/all/reskit/ en-us/part10/c3361.mspx.● "Improving SQL Server Per<strong>for</strong>mance" includes schemas, queries, indexes,transactions, stored procedures, execution plans, and tuning topics:http://msdn.microsoft.com/sql/default.aspx?pull=/library/enus/dnpag/html/scalenetchapt14.asp.● "How To: Optimize SQL Queries" is available athttp://msdn.microsoft.com/sql/default.aspx?pull=/library/enus/dnpag/html/scalenethowto04.asp.● "How To: Optimize SQL Indexes" is available athttp://msdn.microsoft.com/sql/default.aspx?pull=/library/enus/dnpag/html/scalenethowto03.asp.● "Microsoft SQL Server 2000 Index Defragmentation Best Practices" is available athttp://www.microsoft.com/technet/prodtechnol/sql/2000/ma intain/ss2kidbp.mspx.● "Using Views with a View on Per<strong>for</strong>mance" is available athttp://www.microsoft.com/resources/documentation/sql/2000/all/reskit/enus/part10/c3661.mspx.● "Checklist: SQL Server Per<strong>for</strong>mance" is available athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/dnpag/html/scalenetcheck08.asp.● SQL Server 2000 Operations <strong>Guide</strong>: System Administration has very detaileddiscussions on topics such as indexes, statistics, automation, and memorymanagement:http://www.microsoft.com/technet/prodtechnol/sql/2000/maintain/sq lops4.mspx.● "Microsoft Storage <strong>Solution</strong>s – The Right Storage and Productivity <strong>Solution</strong>" isavailable athttp://www.microsoft.com/windowsserversystem/storage/solutions/rightsolution/rightsolution.mspx.● "Windows 2003 Per<strong>for</strong>mance and Scalability" is available athttp://www.microsoft.com/windowsserver2003/evaluation/per<strong>for</strong>mance/perfscaling.mspx.Appendix B: Getting the Best Out of SQL Server 2000and WindowsThis appendix provides references on various aspects of a SQL Server 2000 deploymentthat can be exploited to ensure optimal per<strong>for</strong>mance in an enterprise environment.Per<strong>for</strong>mance is also critical to scalability.Several of the links provided here have been referenced elsewhere in this guidance, butthey are repeated here <strong>for</strong> your convenience.Per<strong>for</strong>mance

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 349ScalabilityScalability is the capability to handle increased volume of data of Very Large Databases(VLDBs) and activity. The size of the VLDBs may be due to a few large tables, or a largenumber of smaller tables, or a combination of both. Activity scalability is measured in thenumber of user connections, response time, throughput, and so on. <strong>Oracle</strong> and SQLServer are continually working on adding features and functionality which are directed atimproving their respective products to meet these demands. While some of thesefeatures, such as clustering, replication, and parallelism, are highlighted in specificationsheets and documentation, much of the scalability is built in at the lower levels of thearchitecture, such as use of bitmaps instead of lists to represent storage, in-row versusout-of-row data storage, and so on. The overall scalability is, however, dependent notonly on the RDBMS, but also on the hardware and the application. The followingreferences answer questions about scalability related to scaling out, scaling up, datapartitioning, 64-bit architecture, storage technology, operating system, and other relatedtopics.● "Scaling Out on SQL Server" is available athttp://www.microsoft.com/resources/documentation/sql/2000/all/reskit/enus/part10/c3861.mspx.● "SQL Server Scalability FAQ" is available athttp://www.microsoft.com/sql/techinfo/administration/2000/scalabilityfaq.asp.● "Microsoft SQL Server 2000 Scalability Project — Server Consolidation" is availableat http://msdn.microsoft.com/library/default.asp?url=/library/enus/dnsql2k/html/sql_asphosting.asp.High AvailabilityAvailability refers to the ability to connect to and per<strong>for</strong>m actions against the databaseserver, the database, and the data. The features in SQL Server that contribute toavailability are discussed here."SQL Server 2000 High Availability Series" provides the most complete set of whitepapers on planning and deploying a highly available environment containing SQL Server.This series is available at:http://www.microsoft.com/technet/prodtechnol/sql/2000/deploy/harag01.mspx.Also refer to Microsoft SQL Server 2000 High Availability (Microsoft Press, 2003).Apart from covering the hardware technologies, the three SQL Server technologiescovered in this series are:● Clustering● Standby database or log shipping● ReplicationThese topics are discussed under the following headings.ClusteringBoth <strong>Oracle</strong> and SQL Server offer high availability support through the use of clusters ofservers. The two DBMSs depend on the underlying hardware and system software toprovide cluster management to detect and manage failures. SQL Server can be run in anActive-Passive or Active-Active configuration using the Microsoft ClusterServices(MSCS).

350 AppendicesIn<strong>for</strong>mation on Windows clustering and SQL Server failover clustering is available athttp://www.microsoft.c om/technet/prodtechnol/sql/2000/maintain/failclus.mspx.Standby Database or Log ShippingBoth <strong>Oracle</strong> and SQL Server offer the standby database capability where a copy(secondary) of the entire (primary) database is maintained in a separate location toprovide recovery from server node and database failures as well as catastrophicdisasters. Changes made to the primary are captured in redo or transaction logs, shippedto the secondary site, and applied to the standby database. The application of the logs tothe standby database can be controlled to be near-synchronous, or lag behind theprimary to suit recovery needs.For more in<strong>for</strong>mation about SQL Server log shipping, refer to:● The overview on log shipping available athttp://msdn.microsoft.com/library/default.asp?url=/library/enus/adminsql/ad_1_server_8elj.asp.● The FAQ available at http://support.microsoft.com/default.aspx?scid=kb;enus;314515&sd=tech.● "Microsoft SQL Server 2000 How to Setup Log Shipping" available athttp://support.microsoft.com/default.aspx?scid=%2fsupport%2fsql%2fcontent%2f2000papers%2fLogShippingFinal.asp.ReplicationReplication is a set of technologies <strong>for</strong> copying and distributing data and databaseobjects from one database to another and synchronizing the data between them <strong>for</strong>consistency. Replication is based on the master-slave technique (called publishersubscriberin SQL Server) in both <strong>Oracle</strong> and SQL Server. Replication is popularly usedto provide high availability of shared data over a WAN.SQL Server offers the following <strong>for</strong>ms of replication:● Snapshot Replication. This is a materialized view (indexed view in SQL Server)containing a snapshot of data at a particular point in time.● Transactional Replication. This is a progression from the snapshot, with changessent to the subscriber at the transaction level. This enables data modificationsmade at the publisher to be propagated to the subscribers and also enablessubscribers to make occasional updates back to the publisher.● Merge Replication. Merge replication is similar to the multimaster replicationtechnique in <strong>Oracle</strong> that allows several instances of the object available at severalSQL Server sites.For an overview, planning, tools, implementation, and other details of replication, refer tohttp://msdn.microsoft.com/library/default.asp?url=/library/enus/replsql/replover_694n.asp.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 351Features and ToolsA brief overview of some of the tools that are very valuable in managing a SQL Serverenvironment is provided under the following headings.Per<strong>for</strong>mance MonitorPer<strong>for</strong>mance Monitor is the most important tool in monitoring SQL Server per<strong>for</strong>mance.When SQL Server is installed on a server, it adds a set of measuring and monitoringcounters <strong>for</strong> SQL Server instances.In addition to visually monitoring per<strong>for</strong>mance counters, the per<strong>for</strong>mance of SQL Servercan be logged using counter logs. All counters available <strong>for</strong> monitoring are also available<strong>for</strong> logging whose set up is separate from the monitoring.Similar to <strong>Oracle</strong> Enterprise Manager, where events can be set up to track space,resources, availability, per<strong>for</strong>mance, and faults, alerts can be set up to track SQL Serveractivity using per<strong>for</strong>mance monitor alerts and SQL Server Agent.The "Monitoring SQL Server Per<strong>for</strong>mance" chapter in SQL Server 2000 Administrator’sPocket Consultant (Stanek, 2000) is a good reference <strong>for</strong> using Per<strong>for</strong>mance Monitor. Itis available athttp://www.microsoft.com/technet/prodtechnol/sql/2000/books/c10ppcsq.mspx.ProfilerThe SQL Profiler utility can be used to monitor the per<strong>for</strong>mance of instance components,Transact-SQL statements, stored procedures, and auditing activity. This utility provides arobust set of functionality that allows you to optionally include a variety of events, reportin<strong>for</strong>mation (data columns), and filtering capabilities.The article "How To: Use SQL Profiler" provides in<strong>for</strong>mation on how to track long runningqueries and heavily used stored procedures. It is available athttp://msdn.microsoft.com/sql/default.aspx?pull=/library/en-us/dnpag/html/scalenethowto15.asp.SQL Server Health and History Tool (SQLH2)This tool allows collection of data from a running instance of SQL Server which can thenbe reviewed and reported on. For more in<strong>for</strong>mation on SQLH2, refer tohttp://www.microsoft.com/downloads/details.aspx?FamilyID=eedd10d6-75f7-4763-86de-d2347b8b5f89&DisplayLang=en.The tool is especially useful <strong>for</strong> measuring service uptime and per<strong>for</strong>mance trends.DTSData Trans<strong>for</strong>mation Services (DTS) offer import and export of data by providing a set oftools that let you extract, trans<strong>for</strong>m, and consolidate data from disparate sources intosingle or multiple destinations supported by DTS connectivity. By using DTS tools tographically build DTS packages, or by programming a package with the DTS objectmodel, you can create custom data movement solutions tailored to the specialized datatransfer needs.For more in<strong>for</strong>mation on DTS, refer to the "Data Trans<strong>for</strong>mation Services (DTS) inMicrosoft SQL Server" white paper available athttp://msdn.microsoft.com/SQL/sqlwarehouse/DTS/default.aspx.

352 AppendicesQuery AnalyzerT he SQL Query Analyzer is a graphical tool that can be used to execute queries directlya gainst the database. It also has the functionality to debug query per<strong>for</strong>mance problemssuch as Show Execution Plan, Show Server Trace, Show Client Statistics and IndexTuning Wizard.An overview of Query Analyzer is available athttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/qryanlzr/qryanlzr_1zqq.asp.For an overview of some of the important features of query analyzer, refer tohttp://www.sql-server-per<strong>for</strong>mance.com/query_analyzer_tips.asp.Index Tuning WizardThe Index Tuning Wizard allows you to select and create an optimal set of indexes andstatistics based on input from Query Analyzer or a SQL Profiler log <strong>for</strong> a SQL Serverdatabase without requiring an expert understanding of the structure of the database, thew orkload, or the internals of SQL Server.For in<strong>for</strong>mation on the features and use of the Index Tuning Wizard, refer to "IndexTuning Wizard <strong>for</strong> Microsoft SQL Server 2000" athttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsql2k/html/itw<strong>for</strong>sql.asp.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 353Appendix C: BaseliningThis appendix is concerned with creating baselines, capturing statistics, and comparingand reporting results.Creating BaselinesB aselines are a collection of facts and figures that reflect the state of a system. Mostcommonly, the term baseline is used with respect to per<strong>for</strong>mance. In the StabilizingPhase, this term is used to refer to a snapshot of the entire system specification.Unlike a new development pr oject where there is no reference point, the state of thecurrent solution can be captured in a migration project. This can be used as a baselinef or comparison with the migrated solution being tested.After every successfulcycle of testing, it is recommended that all elements, such asscripts, applications, application configuration, database configuration, and databases,a re backed up and are baselined with appropriate tags <strong>for</strong> identification. Baselines fromeach cycle of testing can be compared with each other to see the progression towards asolution that can be packaged <strong>for</strong> production.You should create a baseline during the Stabilizing Phase. These baseline values can beused later while troubleshooting per<strong>for</strong>mance problems and also <strong>for</strong> proactive monitoring.The Per<strong>for</strong>mance Monitor, also known as System Monitor tool, can be used to monitorkey system resources (CPU, memory, Disk I/O, network, as well as SQL Servercounters) while you run the Stabilizing Phase tests.The following tables (A.4 through A.8) list some of the per<strong>for</strong>mance monitor counters thatyou can use <strong>for</strong> creating a baseline. These counters can also be used <strong>for</strong> generalmonitoring of the solution after deployment.Table A.4: Memory ManagementPer<strong>for</strong>mance DescriptionMonitor Counters\Memory\Available Available MBytes is the amount of physical memory availableMbytesto processes running on the computer, in Megabytes. Lack ofmemory puts pressure on the CPU and Disk I/O.\Memory\Pages/sec Pages/sec is the rate at which pages are read from or writtento diskto resolve hard page faults. Hard page faults occurwhena process requires code or data that is not in its workingset or elsewhere in physical memory and must be retrievedfrom disk. Note that some paging will usually be presentbecause of the way the operating system works, but theoptimal level <strong>for</strong> averagepages/sec should be close to 0.

354 AppendicesTable A.5: Network AnalysisPer<strong>for</strong>mance DescriptionMonitor Counters\Network Interface Bytes Total/sec is the rate at which bytes are sent and(Network card)\Bytes received over each network adapter, including framingTotal/seccharacters. Average value should be less than 50% of NICcapacity.\Network Segment\ % The percentage of network bandwidth in use on a networkNet Utilizationsegment. Network Monitor Driver can be installed and used tomonitor the network utilization. The threshold value variesbased on the network configuration.Table A.6: CPU MonitoringPer<strong>for</strong>mance MonitorCounters\Processor% ProcessorTime\Processor\% PrivilegedTime and \Processor\%User Time\System\Contextswitches/sec\System\Processor QueueLengthDescriptionThis counter is the primary indicator of processor activity,and it displays the average percentage of busy timeobserved during the sample interval. It is calculated bymonitoring the time that the service is inactive andsubtracting that value from 100%.* Privileged Time is the percentage of elapsed time that theprocess threads spent executing code in privileged mode.Average values above 10% indicate possible CPU pressure.* User Time is the percentage of elapsed time the processorspends in the user mode.* Privileged Time should be about 15% less than the totalUser Time.This counter indicates the combined rate at which all theprocessors are switched from one thread to another. Thepressure on memory can cause page faults, which cancause an increase in context switch/sec value, and adecrease in the overall per<strong>for</strong>mance.This counter indicates the number of threads in theprocessor queue. There is a single queue <strong>for</strong> processortime, even on computers with multiple processors. Asustained processor queue length of less than 10 threadsper processor is normally acceptable, dependent on theworkload. In other words, there are more threads ready torun than the current number of processors can service in anoptimal way.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 355Table A.7: Disk I/O MonitoringPer<strong>for</strong>mance MonitorCounters\PhysicalDisk\Avg. DiskQueue Length\PhysicalDisk\Current DiskQueue Length\PhysicalDisk\Avg. Disksec/Read\PhysicalDisk\Avg. Disksec/WriteDescription* Avg. Disk Queue Length is the average number ofrequests (both read and write) that were queued <strong>for</strong> theselected disk during the sample interval.* Current Disk Queue Length is the number of requestsoutstanding on the disk at the time the per<strong>for</strong>mance datais collected. These numbers should be less than two perusable physical disk in the RAID array, and may be higheron the SAN systems.Average time in seconds to read/write data to the disk.Table A.8: Monitoring SQL Server MonitoringPer<strong>for</strong>mance MonitorCounters\SQLServer:AccessMethods\Free SpaceScans/sec\SQLServer:AccessMethods\Full Scans/sec\SQLServer:Latches\TotalLatch Wait Time (ms)\SQLServer:Locks(Total)\LockTimeouts/sec and Lock WaitTime (ms)\SQLServer:Locks(Total)\Number of Deadlocks/sec\SQLServer:Databases\Transactions/sec\SQLServer:BufferManager\Buffer cache hit ratioDescriptionNumber of scans initiated to search <strong>for</strong> free space toinsert a new record fragment. Inserts on a heap withclustered index will impact per<strong>for</strong>mance as against aheap with no clustered indexes.Tables with missing indexes, or when too many rowsare requested, end up with unrestricted full scans of thebase table or indexes. This baseline counter can be anindicator of an increase in the use of temporary tablesbecause they do not tend to have indexes.SQL Server uses latches to protect the integrity ofinternal structures. This counter monitors the total waittime <strong>for</strong> latch requests that had to wait in the lastsecond.Lock Timeouts counter indicates the number of lockrequests that timed out. This includes internal requests<strong>for</strong> NOWAIT locks. Lock Wait Time (ms) indicates thetotal wait time (in milliseconds) <strong>for</strong> locks in the lastsecond. Lock Timeouts should be low and Wait Timeshould be zero.Number of lock requests that resulted in a deadlock.Should be zero.Number of transactions started <strong>for</strong> the database. It is anexcellent indicator of growth related to transaction load.Percentage of pages that were found in the buffer poolwithout having to incur a read from disk. The higher thevalue of the buffer cache hit ratio the better. In atransaction processing system where a set user base is

356 AppendicesPer<strong>for</strong>mance MonitorCountersDescriptionoperating against the database, this value may reach98-99 percent. If this value is small, then addingmemory to the SQL Server may help. This should belooked at with table scan frequency and might indicatethat indexes/partitioning would improve per<strong>for</strong>mance.\SQLServer:SQL Recompilation adds overhead on the processor.Statistics\SQL Re-Compilations/sec\SQLServer:BatchRequests/sec and\SQLServer:GeneralStatistics\User Connections\SQLServer:MemoryManager\Memory GrantsPending\SQLServer:MemoryManager\Target ServerMemory (KB)\SQLServer:MemoryManager\Total Server Memory(KB)Consistent high values <strong>for</strong> this counter should beinvestigated.These counters, along with Transactions/sec, are agood indicator of load on the server.Current number of processes waiting <strong>for</strong> a workspacememory grant. This value should remain around 0.The total amount of dynamic memory the server iswilling to consume. On a dedicated server, this valueshould remain close to the actual physical memory size.The total amount of dynamic memory the server iscurrently consuming. On a dedicated server, this valueshould remain close to the actual physical memory size.You must determine which server you will use to monitor SQL Server. If you runPer<strong>for</strong>mance Monitor on the same machine as the SQL Server, it should not add majoroverhead, except some disk I/O and disk space requirement <strong>for</strong> the per<strong>for</strong>mance log files,depending on counters that you are monitoring and the interval. A large number ofcounters with a short sampling interval might require a lot of disk space; however, largerintervals will produce less accurate results. If you run Per<strong>for</strong>mance Monitor on a differentmachine, be aware that it might congest traffic on your network.For the purpose of creating the baseline, if you have disk space available on the SQLServer machine, it is recommended you run the Per<strong>for</strong>mance Monitor on the samemachine, add as many counters as desired, and use the short sampling interval. Onceyou have established the baseline, <strong>for</strong> proactive monitoring you can monitor just thecounters absolutely required and increase the interval. To create the baseline chart, follow these steps:1. Click Start, then All Programs, then Administrative Tools, and thenPer<strong>for</strong>mance.2. Expand Per<strong>for</strong>mance Logs and Alerts node in the tree in the left pane.3. Right-click Counter Logs and select New Log Settings.4. Provide a name, click OK, add the counters, verify the details on the Log Filesand Schedule tab, and click OK.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 357Capturing StatisticsSome of the points to be considered <strong>for</strong> capturing statistics are:●●●●Types of data. The type of data being captured — qualitative or quantitative.Characte ristic. The statistic must be relevant to the test being per<strong>for</strong>med. It mustsuit the comparisons being made or analysis to be per<strong>for</strong>med. CPU usagemeasurement is an example of a statistic that is relevant to testing.Unit of measurement. The unit of measurement would be dependent on themagnitude of the measured characteristic. An example is measuring andcomparing memory: the unit to be used is bytes or Mbytes.Frequency. The frequency of measurement of a statistic can be a critical decision.Too much data can be cumbersome and too little could be harmful.Some examples of resources on which statistics can be captured are:● Memory usage of the system● Memory usage of the database● CPU usage● Disk I/O rate● Number of user connections to the database● Procedure cache usage● Number of transactions executed per second● Data cache usage● Network bandwidth usageComparing and Reporting ResultsTest results have only as much value as the inferences that can be drawn from them.Test results can have either a qualitative value or a quantitative value. In a developmentproj ect, the expected behavior of the solution is based solely on business requirements.For a migration, measurements from the existing solution <strong>for</strong>m the expected result.During the testing, the data from the migrated solution is compared with the expectedresults. Deviations from expected results cannot be construed as defects. As a result,analyzing and reporting results is a topic of serious consequence. A thorough analysis ofthe results has to be made and conclusions drawn based on several measurable andnon-measurable factors (assumptions). The capabilities of the systems available <strong>for</strong>per<strong>for</strong>ming stabilization tests may be one such factor.

358 AppendicesAppendix D: Installing Common Drivers andApplicationsThis appendix contains installation in<strong>for</strong>mation <strong>for</strong> FreeTDS, unixODBC, and ActiveStatePerl:● FreeTDS provides an implementation of the Tabular Data Stream (TDS) protocol,emulating the different versions of TDS that are used by <strong>Oracle</strong> and SQL Server.● unixODBC is an implementation of the ODBC protocol and API <strong>for</strong> UNIX; theunixODBC library allows applications r unning under UNIX to communicate withdatabase servers, such as SQL Server, usin g ODBC. Applications developedusing unixODBC can execute under UNIX and SFU.● ActiveState Perl is the industry-standard Perl distribution. This Perl distribution canbe used from within the Window environment.Installing FreeTDSA precompiled and directly installable version of FreeTDS (currently version 0.62.3) isavailable at http://interopsystems.com/tools. This can be installed under SFU 3.5 usingthe pkg_add command. The package ca n be downloaded fromConfiguring FreeTDSWhen FreeTDS is installed, you should configure it to connect to your SQL Serverdatabases using the following procedure: To configure FreeTDS connectivity, follow these steps:1. Move to the /usr/local/etc directory and edit the freetds.conf file. This file containsin<strong>for</strong>mation about the Sybase and SQL Server database servers it can access andthe versions of T DS to use.2. Add the following entries to the end of the file. Replace aa. aa.aa.aa with the IPaddress or DNS name of the UNIX computer running SQL Server (DNS name isrecommended), and bbbb with the port that SQL Server is listening to on thiscomputer (SQL Server usually listens on port 1433) .[SQLServer]host = servernameport = bbbbtds version = 8.0Note The name, SQLServer, does not have to be the same as the name of thecomputer running SQL Server — it is an identifier used by the FreeTDS libraryfunctions to locate the entry in this file. It is a name that uniquely identifies thisentry in the configuration file, and is used wi th the -S option <strong>for</strong> most of the scripts.3. Save the file.Testing the FreeTDS ConfigurationYou can test the FreeTDS configuration using tsql, a tool provided with FreeTDS, byfollowing this procedure:

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 359 To test the installation of FreeTDS, follow these steps:1. At a shell prompt, type the following command. Replace server with the entry infreetds.conf that you want to test (SQLServer), and password with the sa password<strong>for</strong> the selected server:–U sa –P passwordWindows NT Authentication, called "integrated security," is not supported byFreeTDS.2. At the 1> prompt, type the following commands. The result should be a list ofdatabases available on the selected server:SELECT name FROM sysdatabases4.tsql –S serverGo3. At the 1> prompt, type the following commands. The result should be a list ofconnections currently established to the selected server:EXEC sp_whoGoAt the 1> prompt, type the following command to leave tsql.exitInstalling unixODBCunixODBC is available in source <strong>for</strong>m (in the file unixODBC-2.2.6.tar.gz) from theunixODBC Web site at http://www.unixodbc.com. This guide uses unixODBC version2.2.6. The procedures assume you have already downloaded the file unixODBC-2.2.6.tar.gz. To install unixODBC in UNIX, follow these steps:1. Log in to UNIX as the root user.2. At a shell prompt, access the directory where the downloaded unixODBC sourcecode is located (default/usr/local/unixODBC), and then type the following commandto unzip the file unixODBC-2.2.6.tar.gz to the file unixODBC-2.2.6.tar.gunzip unixODBC-2.2.6.tar.gz3. Type the following command to unpack the file unixODBC-2.2.6.tar into thedirectory unixODBC-2.2.6:tar xvf unixODBC-2.2.6.tar4. Move to the unixODBC-2.2.6 directory and type the following command togenerate the files needed to build unixODBC. This command will generate anumber of messages on the screen as it examines your UNIX configuration andgenerates the appropriate make files../configureNote The configure script uses a number of well-known tricks to ascertain whichtools and libraries are available that it can use to compile unixODBC. If theconfigure script fails, it is usually because the script cannot find a particular tool,file, or library. You can run the script supplying parameters to help it analyze yourenvironment. Execute ./configure -h <strong>for</strong> more details.5. Type the following command to build unixODBC. As be<strong>for</strong>e, you will see a largenumber of messages as the build process progresses:make6. Type the following command to install unixODBC:make install

360 Appendices7. Type the following command to check that unixODBC was installed successfully:/usr/local/bin/isqlIf unixODBC is installed correctly, you will see the following message:*********************************************** unixODBC - isql************************************************ Syntax**** isql DSN [UID [PWD]] [options] ** ** Options *** -b batch.(no prompting etc)*** -dx delimit columns with x ** -x0xXX delimit columns with XX, where *** -wx is in hex, ie 0x09 is tabwrap results in an HTML table*** -c column names on first row. ** (only used when -d) ** -mn limit column display width to n ** -v verbose. ** --version version ** ** Notes** isql supports redirection and piping**** <strong>for</strong>*batch processing. *** Examples **** cat My.sql | isql WebDB MyID MyPWD -w ** ** Each line in My.sql must contain ** exactly 1 SQL command except <strong>for</strong> the ** last line which must be blank. ** ** Please visit; ** ** http://www.unixodbc.org ** pharvey@codebydesign.com ** nick@easysoft.com ***********************************************Installing ActiveState PerlActiveState Perl can be downloaded from the ActiveState Web site athttp://www.activestate.com. ActiveState Perl is available in prebuilt binary <strong>for</strong>m <strong>for</strong> Linux,Solaris, and Windows, but the source code is also available and can be used to buildActiveState Perl on other UNIX plat<strong>for</strong>ms.

<strong>Solution</strong> <strong>Guide</strong> <strong>for</strong> <strong>Migrating</strong> <strong>Oracle</strong> on UNIX to SQL Server on Windows 361This section describes how to install ActiveState Perl using the prebuilt Microsoft Installer(MSI) package ActivePerl-5.6.1.635-MSWin32-x86.msi. To install ActiveState Perl under Windows, follow these steps:1. Execute the file ActivePerl-5.6.1.635-MSWin32-x86.msi. Windows Installer startsthe installation.2. In the ActivePerl 5.6.1 Build 635 Setup screen, click Next.3. In the ActivePerl 5.6.1 Build 635 License Agreement screen, select I accept theterms in the License Agreement and click Next.4. In the Custom Setup screen, make sure all features are selected to be installed(the default) and click Next.5. In the New features in PPM screen, clear the checkbox <strong>for</strong> Enable PPM3 to sendprofile info to ASPN and click Next.6. In the Choose Setup Options screen, check all four options and click Next.7. In the Ready to Install screen, click Install. The Installing ActivePerl 5.6.1 Build635 screen will appear and indicate the progress of the installation process.8. In the Completing the ActivePerl 5.6.1 Build 635 Setup Wizard screen, removethe check mark from Display the release notes and click Finish.

362 AppendicesAppendix E: Reference ResourcesFor detailed discussion of the concepts and practices presented in this guide, you shouldrefer to the following resources.● For additional in<strong>for</strong>mation on migration, refer to the UNIX Migration Project <strong>Guide</strong>(UMPG) atHTUhttp://www.microsoft.com/technet/itsolutions/migration/unix/umpg/default.mspxUTH.● Details about Windows Services <strong>for</strong> UNIX (SFU) are available atHTUhttp://www.microsoft.com/windows/sfu/productinfo/overview/default.aspUTH.● Microsoft <strong>Solution</strong>s Framework (MSF) models and disciplines are available atHTUhttp://www.microsoft.com/msfUTH.● For guidance on the structure of operations, refer the Microsoft OperationsFramework (MOF) available at HTUhttp://www.microsoft.com/mofUTH.● For additional in<strong>for</strong>mation on migrating UNIX applications to Microsoft Windows,see the UNIX Application Migration <strong>Guide</strong> atHTUhttp://go.microsoft.com/fwlink/?LinkId=30832UTH●●●Specific guidance on the Microsoft Operations Framework (MOF) quadrants isavailable in the "Process Model <strong>for</strong> Operations" white paper atHTUhttp://www.microsoft.com/technet/itsolutions/techguide/mof/mofpm.mspxUTH.For specific guidance on operating the solution, download the <strong>Migrating</strong> HighPer<strong>for</strong>mance Computing (HPC) Applications from UNIX to Windows guide atHTUhttp://go.microsoft.com/fwlink/?LinkID=23112UTH.For monitoring the deployed solution, refer toHTUhttp://www.microsoft.com/business/reducecosts/efficiency/manageability/default.mspxUTH.● For best practices regarding monitoring, refer toHTUhttp://www.microsoft.com/business/reducecosts/efficiency/manageability/bestpractices.mspxUTH.● For planning a SQL Server 2000 installation, refer to the Microsoft Web site atHTUhttp://www.microsoft.com/sql/techinfo/planning/default.aspUTH.● For programming SQL Server 2000, refer the developer topics atHTUhttp://www.microsoft.com/sql/techinfo/development/2000/default.aspUTH.● SQL Server Books Online is available at HTUhttp://msdn.microsoft.com/library/enus/startsql/getstart_4fht.aspUTH.● For SQL Server 2000 Resource Kit in<strong>for</strong>mation, refer the Microsoft Web site atHTUhttp://www.microsoft.com/sql/techinfo/reskit/default.aspUTH.● For managing and maintaining SQL Server 2000, refer the SQL Server 2000Operations <strong>Guide</strong> atHTUhttp://www.microsoft.com/technet/treeview/default.asp?url=/technet/prodtechnol/sql/maintain/operate/opsguide/default.aspUTH.